There was a war. It happened years ago, maybe even thousands of years. Characters reference it, especially if they took a part in it: the ShellShockedVeteran never managed to get over what he experienced back then, while the PhonyVeteran, on the other hand, will never shut up about how many brave things he did in it.

Sometimes people will use the war as a reference point for placing events on a timeline - something happened a few years before the war, or somebody did something after the war.

Maybe people still have to deal with its consequences. The war happened, and it left its ugly mark on the world. But it's [[TakeOurWordForIt never shown to the audience]] - we never see a single {{flashback}} from the war, are never shown more than just a glimpse of what happened. The war will be referenced, but otherwise left mysterious, unexplained. Why it happened, how it ended, and what all the things that took place there (which people talk about [[CrypticBackgroundReference like it should be obvious]]) actually were, are never explained. The war is only a mysterious event of the past, included mostly to add a bit of mystery and [[WildMassGuessing give people excuses for insane ideas]]. Needless to say, this trope can easily be processed into FanficFuel.

WorldWarIII is often used as this, as are [[WorldWarWhatever the Fourth, Fifth, Sixth and so on]]. Stories set AfterTheEnd have the tendency to do this with the war that caused the apocalypse. If the war never stopped, may be a ForeverWar.

Often used as a sub-trope of CrypticBackgroundReference. Compare also CataclysmBackstory.

Please, avoid shows referencing RealLife conflicts. We already have plenty amount of information on them.



[[folder:Anime and Manga]]
* ''Anime/GhostInTheShellStandAloneComplex'' is set sometime after both WorldWarIII ''and'' IV.
* ''Anime/CodeGeass'' has the Britannian invasion and conquest of Japan, which we see only in flashbacks concerning young Lelouch, Suzaku and Nunally and the one from first episode opening sequence. There also was an alternate version of the Napolean wars, where Napoleon conquered Great Britain, making all the British aristocracy run to America, creating the Britannia Empire.
* The many wars of the Ancient Belka in ''Franchise/LyricalNanoha''. We have been told some general info about it, such as how it destroyed Old Belka and [[YearZero led to the current age]] where physical-based weapons were banned, but otherwise, it's a big question mark. These wars were not visually depicted until ''Manga/MagicalGirlLyricalNanohaViVid'', which revolves around the {{Reincarnation}} of two prominent figures from that war.
* ''Anime/CowboyBebop'' has the War on Titan, which shaped the lives of Spike, Vincent, and Grencia years before any action related to the main story took place. We get a few glimpses of it in flashbacks however.
* ''Anime/LastExile'' also has the war between its two major powers, which is mediated by The Guild. Much of the action of this war takes place BEFORE the actual story, as a few episodes in we discover that [[spoiler: one of the planets these factions live on is dying, essentially taking them out of the conflict for good. They're pretty much refugees after this point.]]
* In ''Anime/BlueGender'', we don't actually see humanity get overtaken by the Blues.
* The War with "Them" in ''Anime/SoundOfTheSky'' is a complete mystery that has become filled with myths.
* Mysterious conflict with ''Anime/MazinkaiserSKL'', whose consequences are related to events of the series.
* ''Manga/{{Naruto}}'' has the first three Shinobi World Wars; though they play a major role in the backstories of a good chunk of the main cast, we still know very little about these conflicts outside of a few offhand mentions and short flashbacks, plus a single gaiden story starring Kakashi.
* The war between [[TheFederation Megalomesembria]] and [[TheEmpire Hellas Empire]] in ''Manga/MahouSenseiNegima''.
* ''PumpkinScissors'' begins with the graduation ceremony of a class of army cadets being interrupted by an announcement that the war everyone thought they were going to be sent to fight in had just ended. The series itself is about a team working to help repair all the damage that was inflicted on their country during the war.
* The war between the [[spoiler: Spiral Warriors and the Anti-Spirals]] in ''Anime/TengenToppaGurrenLagann''. Parallel Works #8 details this a little focusing on Lordgenome's involvement.
* In ''Anime/NeonGenesisEvangelion'' several wars broke out a few days after the Second Impact, one of which resulted in the destruction of Tokyo. We know nothing about these wars other than what's mentioned in [[ Shinji's history textbook]].
* ''Manga/{{Bleach}}'': Shinigami and Quincies have been opposed for over a millenium with two periods of warfare being very important for the main storyline. The first is the original war between Yhwach and Yamamoto that occurred a thousand years ago and led to the creation of the Quincy Clan and the Gotei 13. The second is the Shinigami's attempted [[ThePurge purge]] of the Quincies 200 years ago. Both wars significantly impact the present-day Quincies and Shinigami, including anyone they associate with, be they human or hollow.
* In ''Anime/SuperDimensionFortressMacross'', the backstory tells of a massive war between the Zentradi and a group known as the Supervision Army. The war ended long ago, and Britai's force is conducting mopping-up operations when they come across the Macross. The storyline is carried into ''Anime/{{Macross 7}}'', where we get some understanding of what the Supervision Army was, but the war itself is still an offscreen event.
** According to official sources, the war haven't ended, even with the initial demise of the Protodeviln. Take note that the Supervision Army consisted half of the Zentradi population as well as their total asset. Britai's actions in the beginning of Super Dimension Fortress Macross was an attempt to clear Supervision Army remnant in the sector entrusted to him, but nothing more. Many Zentradi fleets are still actively engaged in battle against Supervision Army forces far outside of the Milky-Way galaxy, and are far too busy to take note of humanity's affairs. Fortunately for the humans, the lack of Zentradi attention gave the former an opportunity to create a domain that encompassed 1/3 of the known galaxy.
** There is also a WorldWarIII fought on earth, that leads to a OneWorldOrder. Though a prequel ''Anime/MacrossZero'' covers some characters actions in it, most of the factions and causes are kept vague.
* Heavens War in ''Anime/DarkerThanBlack'' serves as the backstory for most of the main characters, and is the driving force behind Hei's actions [[spoiler: his sister Pai disappeared at the end when Heavens gate exploded, and Hei is trying desperatly to find her.]]
* ''Manga/NausicaaOfTheValleyOfTheWind'' has the Seven Days of Fire, in which the God Warriors were unleashed on the world and industrial civilization was destroyed.
* Something like this was suggested in the dub version (but not the original version) of ''Anime/YuGiOh5Ds''. When Bommer summons his Flying Fortress SKY FIRE to use against Crow, Crow is naturally freaked out (as most of Bommer's opponents are when he summons it) and exclaims "That's not a monster, that's World War IV!" The implication, of course, is that World War III has occurred in the time period between the present day and [[TwentyMinutesIntoTheFuture this future time.]]
* Subverted in ''Anime/SpaceDandy'', where the war isn't so much off-screen as that the narrator completely forgets to mention it. It pops up now and again, but typically does not have much impact on the story [[spoiler: until the last episode.]]

[[folder:Comic Books]]
* In the second arc of ''ComicBook/TheAuthority'', Jenny Sparks mentions how Earth cut down all connection with the alternate Universe, The Sliding Albion, after the First World War erupted there. Characters from Albion mention briefly that between that event and Albion's invasion on Earth, that world has seen ''eight'' other world wars.
** Also, the fourth story arc (and first written by Creator/MarkMillar) showed us a glimpse of another alternate Earth, which had thirteen continents. A world war that erupted there ended with armies of [[UsefulNotes/AdolfHitler Ado]][[CompositeCharacter lf]] [[MalcolmXerox X]] exterminating all non-black people on ''all'' of them. The Engineer finds the idea of sending a group of superpowered white supremacists there quite interesting.
* Venado Bay in ''ComicBook/{{Legion of Super-Heroes}} V4''. In the retroboot Legion, the backstory of the planet Durla ([Chameleon Boy's home) is the Six Minute War, the nuclear fallout from which left the planet barely habitable and is the origin of their VoluntaryShapeshifting.
* ''ComicBook/StarWarsLegacy'' has the conflict between Galactic Republic and Empire, won by the latter, who then got into the war with the Sith.
* The IDW ''Transformers'' continuity has a few that happened either before or sometime during the onscreen war between the Autobots and Decepticons, which has recently ended:
** The First Great War, which happened several million years before the comics. We don't know much about it, but [[NobleBigot Nova Prime]] and his allies managed to bring it to a peaceful conclusion leading the Cybertronion Golden Age.
** The Software Wars, we know next to nothing about this one, except that [[AxCrazy Guzzle]] was in them and it was centered in the city of Polyhex.
** The Lava Wars, again, we know next-to-nothing about this one. Apparently it was caused by a guy called Magma.
** The war amongst the Stentarians between the Ammonites and Terradores. It's apparently ongoing, is older than all the other known galactic wars, and caused The Shattering, which eventually led to the formation of [[TheAlliance the Galactic Council]].
* ComicBook/ArchieComicsSonicTheHedgehog has the aptly named Great War between the Mobians and Overlanders (aka. the descendants of humanity). It was started when the KnightTemplar Kodos killed two scouts from both sides and sent them too their respective sides, causing some seriously long-standing racial tensions to explode. It lasted for five years and ended when [[BigBad Dr. Robotnik]] (back when he was still called Kintobor) supposedly switched sides and gave the Mobians what they needed to drive back the Overlanders. Unfortunately, after the Mobians won, Robotnik promptly ''[[TheChessmaster betrayed them]]'' too and overthrew the king with his badnik army. Many of the comic's older characters were in the war and there's still plenty of resentment and bigotry left over from the war.
** There's also the first year of the Second Robotnik War, which saw Dr. Eggman regain his power base and promptly retake Mobius after Sonic had been thought killed in battle.
* SonicTheComic and the online continuation SonicTheComicOnline has the Great War between the Echidnas of Megopolis City and the Drakons of the invading Drakon Empire which took place eight thousand years ago over Mobius' Emerald mines which could contain the Chaos energy, a powerful but highly unstable energy source created by scientists on Drak the Drakons home planet, the Drakons were able to steal seven Emeralds before the war began. The gems, when combined with the Chaos energy, formed the legendary Chaos Emeralds. Two days before the war began, Pochacamac, leader of the Megopolis tribe, managed to steal the sacred Emeralds back from the Drakons, both to keep to return them to their true home and to prevent the Drakons from conquering the entire galaxy. Angered, the Drakons sent out a scout to examine the Echidna defenses before sending a full-scale invasion force to claim the Emeralds. A battle erupted inside Pochacmac's command room, with Drakon Prosecutors and Sentinels fighting against Sonic the Hedgehog and echidnas armed with Guardian Robots. The fight was briefly interrupted when a Prosecutor struck the Emeralds with his Dimensional Staff, causing a chain reaction that turned a fallen Drakon warrior into the mighty Chaos. The ensuing explosion weakened the gathered Drakon soldiers enough for Knuckles and the other tribesmen to fight back while Sonic and Pochacmac took care of Chaos. After a final push, the echidnas drove the Drakon invaders out of the city, but the war was far from over. Although no victor was ever declared, the failure of the Drakons to claim their intended prize suggests the Mobian defence held out, albeit at a great cost.

[[folder: Fan Works]]
* In ''FanFic/{{Frontier}}'', a ''MassEffect''[=/=]''StarWars''[=/=]''VideoGame/{{Borderlands}}''[[spoiler:[=/=]''{{Halo=}}]]'' MassiveMultiplayerCrossover, it's revealed that the geth Consensus tied up the BigBad so much that its full force is never applied to the heroes. [[FridgeHorror Keep in mind how many casualties they suffered anyway]], so the "full force" of said enemy might have been more like "game over."
* The Private War in ''Fanfic/TheJacksonLegacy'' takes place a decade before the story kicks off.
* In ''Fanfic/WithStringsAttached'', Grunnel talks about how the Tayhil and their monsters conquered most of Baravada some 200 years ago, and how the skahs rose up to take back the place.
* ''FanFic/ThePowersOfHarmony'' has the War of the Sun and Moon, the conflict between Celestia and Nightmare Moon, which in this story is presented as having lasted several years. There are a few flashbacks to it, but for the most part it's offscreen.
** There's also the Blood War between the Metallic and Chromatic dragons, triggered by Discord [[FalseFlagOperation making each side think the other killed their leader/progenitor Io]]. This war lasted for the entire Era of Discord (''centuries'', if not longer), and it was only after his defeat that Celestia and Luna were able to reveal the truth and end the war.
** Discord ''also'' started a war between the Crystal Ponies and the other races inhabiting Tarandus, which led to the formation of the Crystal Empire (which originally lived up to the [[TheEmpire name and trope]].
* ''FanFic/ToTheStars'' has the Unification Wars between the United Front and Freedom Alliance. Most of the details are AllThereInTheManual.
* ''FanFic/QueenOfAllOni'': The Red King's Rebellion, wherein Tarakudo overthrew the [[PredecessorVillain Oni Elders]]. We only see a portion of the FinalBattle, spread out over two separate flashbacks.
* The War in Heaven from ''FanFic/JusticeLeagueOfEquestria''; we don't know much about it, [[spoiler:just that [[BigGood Athena]] battled and defeated [[BiggerBad Darkseid]] and the forces of Apokalips]].
* ''FanFic/UtopiaUnmade'' has the Bad End War that took place in the past, where Pierrot took control of Märchenland, renamed it the Bad End Kingdom, and attacked Majorland. The Precure Kingdom aided Majorland and eventually exterminated all the residents of the Bad End Kingdom. This was when Love realized the Precure Kingdom was heading towards something bad.
* ''FanFic/FalloutEquestria'' has the war between the zebra and Equestria, which ended much like in the original Fallout (again, it's almost confirmed that the zebra fired first). We actually hear a great deal about what happened in the background of the war, but still almost never see a battle fought.
* There is the occasional mention of the Battle of Al'Zahur in ''Fanfic/WarriorsOfTheWorldSoldiersOfFortune'' that took place fourteen years prior to the fic. All anyone knows about the war is that it was "between mercenaries and the Chivalry", and that Valkron was part of it. He's reticent on the subject, but he does imply that it changed a lot about how the way things were run in the Kingdom afterwards.
* "Fanfic/ShakedownShenanigans": The current 40 Eridani Starfleet Construction Yards are built on the site of a Vulcan yard that was destroyed by a Romulan raid during the Earth-Romulan War 250 years earlier. The ongoing Federation-Klingon War also gets mentioned as the reason for the USS ''Bajor'''s construction (she's primarily a line battleship to replace combat losses) but doesn't play a role in the plot.
* Several times in ''FanFic/SonicXDarkChaos'', mostly because the author has admitted that he isn't good at writing battle scenes.
** The Demon-Seedrian War, which ended in the creation of Tsali and the near-extermination of Cosmo's race, is a major part of the backstory frequently alluded but never actually shown. The author began to write a prequel to explore it, but it was scrapped.
** The battles between the Demons and Angels aren't really shown either - the story focuses more on [[WarIsHell the effects of said battles]] and the political machinations behind the scenes.
* ''Fanfic/BeyondTheWindingRoad'', a ''Manga/PandoraHearts'' {{Continuation}} fic, has the Great Tousterre War. Paralleling World Wars I and II, the great political mess left by the events in the manga led to a massive, bloody war between Sable and its invading neighbors. The war has political ramifications even a century later.

[[folder:Film -- Live-Action]]
* When watching ''{{Airplane}}'', they never make clear which war "The War" was for Ted Stryker, though judging by when the movie was made, one might assume Vietnam. As farcical as the entire movie is, it could very well have been some other war entirely though. Hell it could be a war they (or Ted) completely made up as well. In one scene Ted starts having flashbacks which are represented by StockFootage going farther and farther back, all the way through World War I biplanes and finally the Wright brothers test flight.
** "The War" in ''Film/ZeroHour'', the film on which ''Airplane!'' is based, and which came out a quarter of a century earlier, was obviously UsefulNotes/WorldWarII. This time frame informs a lot of the gags and references in the latter film.
* ''Film/{{Ida}}'' is set in Poland in 1961, 16 years after the end of World War II and a decade or so after the show trials at the height of Communist oppression. Both of those traumatic experiences hang over the entire film. Ida is in search of the truth about her parents, Polish Jews whe were murdered during the war. Although Wanda doesn't admit it, she obviously feels guilt over her role as a HangingJudge during the Communist show trials of the early 1950s.
* ''Film/TheLordOfTheRings'' begins with Galadriel recounting the story of the last war with Sauron, several thousand years prior. We only see the end of the final battle.
* ''Film/{{Maleficent}}'s'' backstory includes a war between humans and TheFairFolk. While the film only makes small reference to it, the [[AllThereInTheManual novelization]] expands on this; notably, it was in this war that Maleficent's parents were killed. The film itself shows the two races living in segregation, though the ending implies that [[spoiler: ''Queen'' Aurora]] will bring peace between them.
* The Clone Wars were this for the ''Franchise/StarWars'' trilogy until the prequels came, then two cartoons and a lot of other things that explored it, so it ultimately avoids this trope.
* ''[[Film/TheTimeMachine1960 The Time Machine]]'' (1960): In-Universe. The protagonist from 1899 traveled a couple of decades into the future. One of his friends' sons mention "the front" of "the war". It's obvious its the First World War, but being a time-traveler, he was unaware.
* A plot point in ''Film/{{Rollerball}}''. Whenever the protagonist tries to find out details about the [[CorporateWarfare Corporate Wars]] he finds himself hitting a brick wall, as America is OneNationUnderCopyright and doesn't want its skeletons in the closet being aired.
* The war against the Sentinels in ''Film/XMenDaysOfFuturePast''. When the film starts, the war is over, and the Sentinels are just hunting the last mutant survivors.
* ''Film/{{Seventh Son|2015}}'' is set about a century after a war waged by evil witches on humanity, which the world is said to still be recovering from.
* In ''Film/StarTrekInsurrection'', the [[Series/StarTrekDeepSpaceNine Dominion War]] is treated like this.

* The ''Literature/{{Discworld}}'' series has two examples - the wizard wars which serve as an example of why wizards shouldn't actually cast spells, and the wars of the Evil Empire, which serve as the origin story of the Orcs. The latter may or may not be the same as the "big old wars" mentioned in "Troll Bridge", in which Cohen the Barbarian fought for a bright new future and the [[ShoutOut return of the king]], and Mica the troll fought because a big troll with a whip told him to.
* ''Literature/HarryPotter'' series:
** The First Wizarding War against Voldemort.
** The war against Gellert Grindelwald is even more obscure. All we know for sure is that it apparently took place around the same time as World War II. Fanon consensus is that Grindelwald and ThoseWackyNazis had some sort of alliance. WordOfGod is that the timeframe and location of the war against Grindelwald are not a coincidence, but is vague on whether this was just a deliberate parallel to WorldWarII by the author or an indication that they were actually the same war.
* Twice in ''Literature/TheHungerGames:'' the [[AfterTheEnd civilizational collapse]] that led to the founding of [[PoliceState Panem]], and the more recent "Dark Days" when Panem's provinces rose in an unsuccessful rebellion against the Capitol.
* The [[ Butlerian Jihad]] is repeatedly mentioned in the original ''Franchise/{{Dune}}'' series and had a profound effect upon the setting. [[FranchiseZombie After Frank Herbert's death]], his son Brian and Kevin J. Anderson wrote a [[Literature/LegendsOfDune prequel trilogy]] to flesh out the details. [[FanonDisContinuity But the fans try not to talk about those.]]
* Bujold's ''Literature/VorkosiganSaga'' is full of these. Mad Yuri's War, the Cetagandan Invasion, the Komarr Conquest and subsequent Revolt all have a direct impact on the storyline decades after they took place.
* The [[AlienInvasion Psychlo invasion]] in ''Literature/BattlefieldEarth'', which lasted about [[CurbStompBattle 9 minutes]].
* In Creator/SergeyLukyanenko's ''[[Literature/NightWatch Watches]]'' books, the Treaty is signed between the Light and the Dark Others after a magical war that nearly destroyed everything. Hardly any details are revealed about the war. The beginning of TheFilmOfTheBook ''Night Watch'' shows a battle between two groups of barbaric-looking people without using any magic (the director hates magic), with each group consisting of two dozen men at most. This is likely meant to be [[WhatDoYouMeanItsNotSymbolic symbolic]], though.
** Later novels flesh out more details. In ''The Last Watch'', Anton sees a vision of a battle that took place long ago that ended when Gesar and Rustam used a spell devised by Merlin to collapse the layers of the Twilight in a certain area, turning both the Dark Others and their human armies into [[AndIMustScream living statues]].
** In ''School Supervision'', it's revealed that {{Ghostapo}} was real in that some Others participated in WorldWarTwo on the side of the Nazis and used magic against the Allied-aligned Others. [[UsefulNotes/TheCityFormerlyKnownAs St. Petersburg]] was the site of the biggest magical battle of the war, likely contributing to it becoming a GeniusLoci in ''The Face of the Dark Palmira''.
* Creator/LarryNiven's ''Future History'' (leading to Literature/KnownSpace) series deals heavily with relations between humans and the Kzin, but the early Man-Kzin Wars never showed up in the books just because Niven didn't like writing war stories. He did let other writers go back and fill that in later, though.
* The aptly-named Vague War in Creator/SergeyLukyanenko's ''LineOfDelirium'', which takes place decades prior to the novel. Many references are made to the war, but few details are revealed. Apparently, it was a big free-for-all with all known races but no alliances. The war led to the formation of the [[TheEmpire Human Empire]]. The author even throws in a funny story about humans spreading misinformation about their dietary needs (i.e. that we need spinach to survive). The aliens spend resources developing a spinach-killing virus and lose countless ships spreading it throughout the human worlds. When humans don't die, they [[OhCrap surrender out of shock]]. On a less funny note, good luck finding spinach after the war.
* The Aiel War in ''Literature/TheWheelOfTime'' is mentioned in passing by numerous veteran Warders, Tam al'Thor, and others. Many other wars - the Breaking of the World, the War of a Hundred Years, Artur Hawkwings war of consolidation, all serve to create rich background for the series.
** The ending at least of the Aiel War was covered in the {{Prequel}} novel, ''New Spring.''
* ''Literature/TheReynardCycle'':
** At the outset of the series, there has been a civil war raging in Arcasia for over a hundred years. The Countess Persephone's father was slain in it, Duke Nobel proved his skill as a military commander during it, and Bruin, Tiecelin, and Grymbart fought in it, occasionally referencing battles, camp life, what the weather was like before an engagement, etc. The war drove an entire region to famine so extreme that its people had to resort to ''eating their own children'', and yet its over before page one of ''Reynard the Fox''.
** More cryptically, there are occasional references to "The Glyconese Rebellion", an ancient war in which ''dragons were involved.''
* In the ''[[Literature/SwordOfTruth The Sword of Truth]]'' series, many of the {{MacGuffin}}s, events and plots of the entire series are a result of the direct influence of the events in the Great Wizard War that happened over 3000 years ago.
* ''Literature/ASongOfIceAndFire'' has many of these. The most important is Robert's Rebellion, which is really the cause for all of the events in the series - giving the effect that the reader has plunged into [[InMediasRes the middle of the story]] rather than the beginning. More recently, there was Balon Greyjoy's Rebellion. Further back in time, we had the Targaryen Conquest and the War of the Ninepenny Kings. The ''Literature/TalesOfDunkAndEgg'' prequel series features the fallout of the Blackfyre Rebellion. Going even further back then that, back to mythic times, there are the stories from various cultures about a great battle between good and evil, implied to be an earlier war with [[BigBad The Others.]]
** What Tywin Lannister did to inspire "The Rains of Castamere". "But there are no Reynes and Tarbecks"... "[[AppealToObscurity Exactly]]."
* From ''Literature/HonorHarrington'':
** Admiral Theisman's purge of the StateSec forces which refused to fall in line with the new government after the overthrow of the Committee of Public Safety. The only part of it shown is from ''The Fanatic'', which itself took place away from the meat of the action. Not a typical example, as that particular conflict took place between two of the later books of the series.
** Earth's "Final War" many centuries before the current timeline, where the planet was nearly rendered completely uninhabitable until several colonies sent aid to repair the damage.
* In Creator/JoWalton's AlternateHistory ''Literature/SmallChange'' trilogy, Germany continued fighting on the Eastern Front past 1949; Japan conquered most of China. The novels take place from the detached perspective of England, with word of the continuing war coming in [[CrypticBackgroundReference newspaper headlines and occasional chatter]].
* Creator/StephenKing's ''Franchise/TheDarkTower'' series occasionally reference the last war of the Gunslingers against the Good Man, and it's the backdrop against which ''Literature/WizardAndGlass'' is set. There is also an even older event implied to be a nuclear war, which is why the series is AfterTheEnd in the first place.
* Franchise/StarTrekExpandedUniverse
** In the ''Literature/StarTrekNewFrontier'' series, Calhoun and Picard (and their crews) discover that a species that's apparently been friendly -- the Selelvians -- is actually capable of an insidious level of mind control which they've hidden successfully up until this point. In the next book in the series, there's been a TimeSkip of several years and the Selelvians have been defeated after a fairly vicious war.
** The war is also this trope in the "mainstream" [[Franchise/StarTrekNovelVerse novel 'verse]]. We know that it indeed happened (between ''Literature/StarTrekVulcansSoul'' and the early ''Literature/StarTrekVoyagerRelaunch''), off near the Tholian border, but other than a couple of offhand mentions it's not yet been visited.
* ''[[Literature/{{Lensman}} Triplanetary]]'' mentions the first and fourth Jovian Wars, which resulted in the formation of the Triplanetary League from Venus, Tellus, and Mars.
* The 'Holy War' against the Ghouls in E. R. Eddison's ''Literature/TheWormOuroboros'', in which all the civilized ("polite") nations of the world of Mercury fought alongside each other, and that ended just shortly before the book's storyline begins.
* In ''Literature/NineteenEightyFour'', there is supposedly a vast war raging between the three superstates, but it has no actual bearing on the novel's plot. [[spoiler: Of course, it could just be made up to make the party's rule seem legitimate]].
* Some kind of great war is implied to be happening in ''Literature/LordOfTheFlies''. The reason the children are on the island is because the plane that was evacuating them from a soon-to-be-nuked Britain was shot down.
* One of the ''Barnaby Grimes'' books mentions a war that was fought (possibly still being fought) to the East, in "The Malabar Kush". It included events such as "the siege of Rostopov", "the fall of Dhaknow", and "the storming of the Great Redoubt".
* Stewart Cowley's "Terran Trade Authority Handbooks" opening opus, ''Spacecraft: 2000-2100AD'' purports to be an identification guide of the spacecraft of that era (it's essentially one-page profiles based on spacecraft pictures by illustrators such as Chris Foss and Peter Elson). The smaller ships of the Proxima Wars - Earth and Alpha Centauri vs. Proxima Centauri - from all three races fill the military section, and there are hints of major fleet actions between capital ships early in the conflict. While a few specific battles are touched on in terms of detailing the service histories of the ships that fought them, and the civilian ships built in the wars' aftermath add a smattering of their own history, a full history of the entire war does not exist. There were to have been further TTA handbooks as part of an early 21st Century attempt to reboot the franchise, but these seem to have gone to DevelopmentHell and this troper (a BIG fan as a child) has not been able to locate any of them.
** Cowley played the game again in the follow-on ''Great Space Battles''. One of the ships in the ancient fleet which is resurrected to save humanity when its enemies show a disturbing ability to hack the battle computers of the sophisticated frontline ships (and yes, this predates the reboot ''Battlestar Galactica'' by DECADES) is described as being a veteran of 'countless' Imperial policing actions - but we never get to find out what these are, even though they are serious enough that battleships were required.
* The ''Literature/HostileTakeoverSwann'' series has the Genocide War against the Race, the {{Big Bad}}s of the Literature/MoreauSeries, which destroyed all their colonies. There are still {{Kill Sat}}s in place over their homeworld, programmed to destroy anything that makes orbit.
* ''A Dry, Quiet War'' by Tony Daniel. The protagonist returns to his home planet after fighting a war twelve billion years in the future at the end of time, apparently to hold back the spread of entropy so the universe has a chance to exist in the first place. Not only are few details provided on the war, but the [[GrandfatherParadox actions of the protagonist make it all moot anyway]], and he's forced to return to the future to fight all over again.
* ''Literature/TheSalvationWar'' has constant mentions of the Great War between Heaven and Hell (lasting for a few million years), demons wiping out multiple other races on other worlds, and skirmishes among the demon nobility.
* ''Literature/TheGodslayerChronicles'' by JamesClemens has a back story of a great war between the Gods which ended in the shattering of the Gods' world and splitting the Gods into 3 beings: a flesh but immortal body which landed on "Earth", and 2 non-corporeal forms in the Aether "The Aethryn" and the Naether "The Naethryn".
* In ''Literature/TheRogueKing'' by Aldrea Alien, there was once an empire spanning the whole continent. It fell 2000 years prior to the story's setting.
* Several characters in ''Literature/RememberToAlwaysBeBrave'' are straight from the last of three global wars which started in their 1900s, the Roman-Nipponese war. Immediately before those two, there was the Sino-Roman war and the Roman-Mongolian war, and all three lasted from around the 1900s to 1953, with a nuclear bombing of Japan and the "Peninsula" (Korea) followed by a long, bloody invasion.
* In ''Literature/{{Palimpsest}}'', there are a lot of references to a war that took place at some point prior to the events of the story. Most of the immigrants know it happened, but few seem bothered by the details. [[spoiler:It's eventually revealed that Palimpsest had once closed itself off to immigrants completely, but Casimira went to war against the anti-immigrant group because sorrow and loneliness made her determined to bring the immigrants back. Because she won, people from real life once again got the ability to travel there and possibly stay forever.]]

[[folder:Live Action TV]]
* The Last Great Time War from ''Series/DoctorWho''. It was never shown, we know only that it caused a lot of destruction and wiped out entire races, including the Time Lords, whose last survivor was the Doctor. We find out that the Doctor was the one who ended the war, killing ''every'' Dalek (apart from [[JokerImmunity a few who got away, of course]]) at the cost of also killing ''every'' Time Lord, including his own children and grandchildren. The Doctor has to deal with the consequences of the Time War from time to time and sometimes he or somebody else makes a reference to some events of it, but it's still mostly a mystery.
** Showrunner Creator/StevenMoffat has gone on record saying that he will never show the Time War since there isn't enough money in the world to do it justice.
*** However, in the ''Day of the Doctor'' movie, footage ''was'' shown. ''It is not pretty.''
-->'''Doctor:''' You weren’t there in the final days of the war. You never saw what was born. But if the Time Lock’s broken then everything’s coming through, not just the Daleks, but the Skaro Degradations, the Horde of Travesties, the Nightmare Child, the Could-Have-Been King with his Army of Meanwhiles and Never-Weres – Hell is coming. The war turned into ''Hell''.
** Older episodes referred to similar such events, including the survivors of the destruction of Phaester Osiris defeating Sutekh and sealing him in a pyramid on Mars, or the ancient war between the Time Lords and the Great Vampires shortly after the beginning of time.
** Ancient battles between the Fledgling Empires (including Gallifrey) and the Racnoss were mentioned in "The Runaway Bride".
** The Sontarans have been at war with the Rutan host for at least 60,000 years of the Whoniverse's timeline (mentioned in both ''Series/DoctorWho'' and ''Series/TheSarahJaneAdventures''), and yet we've never encountered a Rutan and Sontaran together on TV once.
** PlayedWith in "The Doctor's Daughter". A war, fuelled by cloning machines, has gone on for 700 generations. It turns out that those 700 generations were cloned, shoved into battle and killed in the space of [[spoiler: one week]].
** The great Cyber-Wars fought between human forces and the Cybermen were mentioned frequently, but the Cybermen were hardly even seen at the height of their power - mostly after the fact as TheRemnant.
* ''Series/StarTrekTheOriginalSeries'' has a lot of those:
** The Third World War and Eugenic Wars, all taking place on Earth and concerning only humanity. It was actually one war in the Original Series, but was later [[{{Retcon}} divided]].
** The war between the Federation and Romulan Empire, which forms the backstory for the episode "Balance of Terror".
** The Earth-Romulan war. When first mentioned in the original series, this war was fought entirely at extreme ranges with nuclear weapons (and with neither race ever actually seeing a member of the other).
** The ongoing war between the Federation and the Klingons at the time of the Original Series is mostly not shown.
* ''Series/StarTrekTheNextGeneration'':
** The war between the Federation and the Cardassians, which was responsible for creating the Anti-Cardassian [[LaResistance Maquis]]. Strangely, it wasn't mentioned in the first seasons, only later.
** The "brutal border wars" against the Talarians and the Tzenkethi, which happened at some point between the ''Original Series'' and ''The Next Generation''. There was also at least one conflict with the Tholians in the same time-frame.
* Both series of ''Franchise/BattlestarGalactica'' have mentioned previous wars with Cylons.
** The new BSG's First Cylon War did eventually get screentime in ''Series/BattlestarGalacticaBloodAndChrome''. A licensed video game also purports to cover that period, even being played from the perspective of Commander Adama as a rookie pilot, but it mixes and matches so many elements of the original series and remake that it probably belongs in its own separate continuity.
* Silicate War, the war with the android revolution, taking place years before events of ''SpaceAboveAndBeyond''.
* The conflict between Dharma Initiative and the Others was only hinted at in the first four seasons of ''Series/{{Lost}}'', though the Season 5 gives us a pretty clear picture of it. The conflict between the Others and the US Army is even more obscure.
* The war with the Magogs from ''Series/{{Andromeda}}'', the end of which caused the [[StrawNihilist Nietzschean]] revolution, may count too, as it started at the beginning of the first episode. The episode then jumps 300 years in the future, to the main plot, not only skipping the downfall of the revolution, but also the civil war among the ones who caused it, the High Guard.
* Played with in ''Series/ThatMitchellAndWebbLook'' where a group of people are holed up in a nuclear bunker playing a game show and broadcasting in the vain hope somebody is actually watching. It all focuses around "The Event"; the only interesting thing any of the characters can think about but are sworn not to talk about for various reasons. The most probable event would be a nuclear war.
** Or alternatively whatever caused the majority of the human population to become zombies ('Them').
* ''Series/BabylonFive''
** The Dilgar War, the first major interstellar war that the humans got involved in, as well as the previous Shadow War, which took place around a thousand years previously. We do see a glimpse of that era, mostly just some less advanced looking Minbari ships, but nothing of the war itself.
** Also the Telepath War. We are shown only before and after.
** And the first Narn war for independence from the Centauri, about 100 years prior to the beginning of the series.
** Along with the numerous wars the Centauri Republic was waging with its neighbors in the third season, none of which are seen, or indeed the numerous smaller wars between the members of the League of Nonaligned Worlds in the same season.
** There are also allusions to various minor conflicts that the Earth Alliance took part in. Not to mention the Earth Minbari War, which we heard much about, but saw little of, until the prequel movie ''In The Beginning''.
** Also, the Drakh War, of which we see practically nothing due the spin-off telling it getting ScrewedByTheNetwork.
** Other important conflicts are the ''other'' Shadow Wars, the war against the [[EldritchAbomination Thirdspace Aliens]], the one against whoever created The Hand (purpoted to be the Thirdspace Aliens in the ExpandedUniverse), the genocidal war between the Centauri and their co-worlder race the Xon, the Shroggen invasion of Centauri Prime the Centauri-Orieni War and the Orieni-Minbari War.
*** The Centauri-Xon War and the Shroggen invasion are particularly important because they're why the Centauri created [[TheEmpire an empire]] and have ChronicBackstabbingDisorder as their [[PlanetOfHats Hat]]. Before first contact, the Xon were a technologically primitive species that lived on Centauri Prime's southern continent, while the Centauri were ''{{Actual Pacifist}}s'' with an unified confederation of four kingdoms and Renaissance-level technology. After Centauri explorers found them, the Xon took over their ships and copied them to invade the Centauri kingdoms, killing everyone who opposed them and enslaving the rest, thus shattering Centauri society that, [[HeWhoFightsMonsters to fight back, reformed on the Noble Houses and then the Centauri Republic, with the power equilibrium kept by their infamous infighting]]. With time and the Xon on full retreat the Centauri ''may'' have returned to a relatively more peaceful society, except that, around the time the Houses created the Republic and developed 20th century-equivalent technology with help from the passing Technomages, the Shroggen invaded (they were actually after the Technomages, but, with their quarry helping the Centauri and themselves being [[AlwaysChaoticEvil Shadow servants]], they launched a full-blown invasion, and the Centauri had to deal with that too. After that they took the stars as conquerors [[NeverBeHurtAgain because otherwise they expected they would be conquered or exterminated]] [[IDidWhatIHadToDo and someone else would conquer or exterminate their subjects]], [[JumpingOffTheSlipperySlope and then started conquering for conquest's sake]].
*** Also, the two wars involving the Orieni. The Centauri-Orieni War is the reason the Centauri are a VestigialEmpire ([[PyrrhicVictory their victory weakened them enough to prevent them from conquering the Fringe Worlds, and the following Civil War caused them to abandon a large part of their empire]]) and Earth Alliance and the League exist at all (the League was born from the Abbai unifying the rest of what the Centauri called the Fringe Worlds with most of the worlds abandoned by the Centauri in a league specifically to prevent a Centauri resurgence, while Earth is extremely close to Centauri space and the war happened from 2001 to 2009, and would have been conquered had the Centauri not been to busy with the Orieni to follow our messages) and the Dilgar War happened at all ([[ForWantOfANail about at that time the Centauri found out the Orieni had recovered, causing the Centauri to redeploy the fleet they were amassing to conquer the Dilgar while they were distracted with their invasion to the border facing the Orieni while they fortified the border systems]]), while the Minbari-Orieni War is why the Minbari didn't have a larger impact on the Drakh War (the Orieni, mad at the other younger races for chasing away their Living Gods AKA the Vorlon (who, when asked, had told them they weren't gods), decided to make them pay starting from the Minbari, and attacked about the same time the Drakh were attacking Earth. Caught by surprise and not having recovered yet from the Earth-Minbari War, the Minbari couldn't just swat them away, and by the time their superior technology allowed them to stem the tide they were effectively crippled).
** {{Subverted}} by the Centauri-Garmak War. Being the conflict that propelled the Centauri from the status of fledgling empire to local superpower by absorbing the Garmak Empire and reverse-engineering their technology, with the addition of leaving them with an healthy fear of the Minbari you'd expect this. The Centauri and the minor powers of the era expected this, and the Centauri planned to start it by assembling their largest fleet ever and attacking the largest concentration of Garmak ships they could find. Then, as they were about to enter weapon range, [[DidntSeeThatComing the Minbari jumped in and wiped out the Garmak fleet before jumping out and do the same to the entire Garmak military]] ([[BullyingTheDragon it turned out the Garmak had raided some Minbari religious outpost]]), and the Centauri, [[OhCrap after recovering from the shock and making sure the Minbari were not after them too and had returned home]], simply marched in and conquered without firing a shot.
** {{Discussed}} by Garibaldi in an introspective moment in season 5 as things move towards war with the Centauri. To paraphrase, he wonders aloud why we always divide history by the wars, not by the periods of peace, and comes to the conclusion that wars are just more fun.
** PlayedWith in one episode when Marcus & Dr. Franklin were being smuggled to Mars. The [[VichyEarth Earth Alliance]] kept out of the Vorlon-Shadow war, so from the perspective of most humans this is the case. Marcus even (sarcastically) lamented coming home as a war hero in a war nobody ever heard about.
* ''Franchise/PowerRangers'' falls back on this one a lot, to the point where EpilepticTrees have grown due to some wars sharing the same rough dates. Some of these conflicts are original while others are carried over from the original ''Franchise/SuperSentai'' counterparts:
** ''Series/MightyMorphinPowerRangers'' had a great battle between Good and Evil 10,000 years ago. Zordon was with the good guys, Rita with the bad guys under the command of Zedd. The only other clue we have about it is the ending: According to some of the novelizations released around the time, the war ended in "a tie" and came down to a frikkin' ''coin toss'' to end the war. Zordon won, but Rita, being a sore loser, trapped Zordon in his Time Warp and stole the Dragon Coin before she and her minions were sealed away in the trashcan. Naturally, nothing like the books' 'coin toss' thing has ever been suggested onscreen. All we know is, Rita got canned, and that Zordon has used teenagers before (though none of Zordon's warriors in flashbacks looked like Rangers.)
** ''Series/PowerRangersLostGalaxy'' is so vague that we don't even know if there was one big event or just a bunch of isolated incidents. Either way, a lot of backstory happened 3,000 years ago. Most of it in deep space, but if the Lights of Orion were found on Terra Venture, then they have to have been left on Earth when they were lost back in the day.
** ''Series/PowerRangersLightspeedRescue'' had Bansheera and company [[SealedEvilInACan put in the can]] 5,000 years ago. Her ''entire'' motivation for attacking in the present is to destroy the city and reestablish her palace upon the demons' sacred ground, granting 'ultimate power.' The fact that she had it then meant she had to have been a lot worse than anything witnessed during the Lightspeed series.
** ''Series/PowerRangersWildForce''/''Series/HyakujuuSentaiGaoranger'' had the war between the Animarian civilization and the Orgs 3,000 years ago.
** ''Series/PowerRangersNinjaStorm'' introduced one of the generals this way; the warlord Shimazu terrorized the populace with his Wolfblades 2,000 years ago until he is sealed in a mask.
** ''Series/PowerRangersMysticForce'' saw a group of wizards seal away the forces of the underworld only twenty or so years prior (so somewhere in or around the 1980s).
** ''Series/PowerRangersJungleFury'' had a war between man and beast 10,000 years ago. Surprisingly, the four of the seven {{Old Master}}s that survived the war also survived to the present day.
** Averted in ''Series/PowerRangersRPM'', where we get a number of flashbacks to Venjix's conquest of Earth the year prior.
** ''Series/PowerRangersSamurai''/''Series/SamuraiSentaiShinkenger'' had the Nighlocks/Gedoushu sealed away by samurai in feudal Japan, and apparently a number of skirmishes between them and the samurai's descendants in the intervening years. ''Power Rangers'' even showed a flashback involving the current Rangers' parents running off to fight as Rangers themselves, which had to have taken place somewhere in the 90s alongside a previous ''Rangers'' series.
** Gloriously averted with the Great Legend War of ''Series/KaizokuSentaiGokaiger'', though the [[TheEmpire evil Space Empire Zangyack]] are said to have had a long history conquering the universe before the invasion of Earth.
** ''Series/ZyudenSentaiKyoryuger'' had the war where the Deboss wiped out the dinosaurs but were ultimately forced into hibernation, along with the two sides being in a cold war that heated up occasionally throughout history.
* In ''Series/TheWalkingDead'', the military is mentioned to have been overtaken by the [[OurZombiesAreDifferent Walkers]] and their abandoned equipment and corpses are seen lying about in the streets of Atlanta and outside of CDC, but it's never shown how the military were defeated.
* The ''Series/{{Firefly}}'' pilot (and one other episode) contain a flashback to the "Independence War", but other than that it's just talked about, although its aftermath is the prime motivation for many of the characters.
* ''Series/KamenRiderAgito'' is a non-direct sequel to ''Series/KamenRiderKuuga'', most explicitly referenced by the police-made G3 PoweredArmor being based on data from Kuuga himself. According to the backstory, Kuuga's old enemies the Grongi fought a war against another monster group, the Lords, who eventually won and became the villains of ''Agito''. ''Series/KamenRiderDecade'' directly references this when the heroes go to an AlternateUniverse version of ''Agito'' and land right near the end of the Grongi-Lord War.
** And of course then there are things like the Rinto Kuuga's battle with the Grongi, the [[Series/KamenRiderBlade Battle Royale]], and [[Series/KamenRiderOOO the original OOO's battle with the Greed]], though that one is not what it seems.
* In ''Series/{{Merlin}}'' there are increasingly frequent mentions of a war waged at some nebulous time before/around King Uther's time in which ancient/recent kings were pitted against the sorcerous High Priestesses.
* The Makhash Wars from ''Series/BuffyTheVampireSlayer''.
* ''Series/{{Scrubs}}'' has the Janitor mention overthrowing Kyle, the former leader the Brain Trust ("A dictatorship masquerading as a democracy") during The Revolution of '02, specifically The Battle of the Basement Supply Closet. [[UnreliableNarrator This probably never happened.]]
* The Insect Wars from ''Series/{{Lexx}}''. Despite only being mentioned once or twice in a couple episodes, the Wars are very important to the plot [[spoiler:since they never really ended. The last surviving Insect passed his essence onto humans to create the Divine Order which helped him revive his original body and wipe out most of the Light Universe's human population in one fell swoop. His Divine Shadow takes great pleasure in telling Kai all of this.]]
-->'''His Divine Shadow''': The victory of your ancestors was not complete.
-->'''Kai''': [[spoiler:You are a survivor of the Insect Civilization!]]
-->'''His Divine Shadow''': ''Yes'', last of the Brunnen-G.
* The civil war in heaven among the angels in ''Series/{{Supernatural}}'' is all off screen, which is likely a JustifiedTrope as [[YouCannotGraspTheTrueForm humans can not perceive the true form of angels without their eyes burning out]].
* ''Series/{{Dominion}}'' has the Extermination War fought between humanity and the angels led by [[ArchangelGabriel Gabriel]]. We saw the opening days of the conflict in ''Film/{{Legion}}'' (the movie to which this show is a sequel), but the show is set 25 years after its conclusion.

[[folder:Multiple Media]]
* The Core War in ''Franchise/{{Bionicle}}'', although we do see a very brief account of its more important moments in one of the {{Flashback}} comics.

[[folder:Tabletop RPG]]
* ''TabletopGame/DungeonsAndDragons'' adventure I12 ''Egg of the Phoenix''. The War of Ending between the forces of Evil and Old Empyrea. Doc and the silver dragon Falx fought in the war, during the adventure the {{PC}}s find a message that dates back to it, and one mission involves scouting one of the Castles of Ruling that played a major part in the war.
** The backstory of the ''TabletopGame/NentirVale'' setting in 4th Edition has the war between the civilization of Nerath led by King Elidyr and the gnoll demon horde headed by Yeenoghu. There was also the war between the tiefling (half-devil) empire of Bael Turath versus the dragonborn empire of Archosia. [[DungeonCrawling Your characters most likely will start their career scrounging leftover supplies from said wars.]]
** An attempt was made to rework the World Of Greyhawk setting with The Greyhawk Wars (the war Iuz was preparing for in the time period of the original boxed set). The war itself was represented as a stand-alone board game only. It produced some interesting novels set in the aftermath of the War where characters often have to deal with the consequences, but the canon version of the war itself is relatively obscure.
* ''TabletopGame/{{Exalted}}'' has a few examples: the Primordial War, the Aftershock War, the Usurpation and the Balorian Crusade. All of these are provided some level of detail (specifically who was fighting and why), but the exact events of the wars are generally shrouded in mystery (typically because they all involved reality being damaged to some degree).
** And those are just wars involving the Exalted. The occasional hint is dropped regarding wars waged by gods in the era before humanity, and even occasionally to conflicts involving the Primordials prior to the existence of Creation.
** Autochthonia has its own version in the Elemental War (so named because it so devastated the mechanical ecology that it drove thousands of elementals violently mad), which was noteworthy for being an extremely violent, ethnically driven total war in a world where most fighting is skirmishes to steal resources and supply lines.
* ''TabletopGame/{{Warhammer 40000}}'' includes a lot of this in the {{backstory}}, such as a RobotWar that explains the Imperium's distrust of ArtificialIntelligence.

* Creator/WilliamShakespeare:
** ''Theatre/AsYouLikeIt'': Duke Senior was (somehow) deposed by his younger brother Fredrick and exiled to the Forest of Arden. A very blatant DeusExMachina at the end restores Senior to his rightful place.
** Old Hamlet's war with Norway in ''Theatre/{{Hamlet}}''.
** Theatre/{{Othello}}'s military record might also count: he boasts at length of his experience with 'pride, pomp and circumstance of glorious war', but we never see him fight.
** ''Theatre/{{Macbeth}}'' begins with a recounting of a war between Scotland and Norway.

[[folder:Video Games]]
* Somewhere between ''VideoGame/MegaManX'' and ''VideoGame/MegaManZero'' series timeline, there occured a great war called the Elf Wars, caused by Dr. Weil corrupting the Mother Elf[[note]]An EnergyBeing made by reverse engineering Zero's viral data and used by X to purge the Maverick Virus off the earth[[/note]] and combining it with his other creation, the reploid Omega, to make reploids wreck havoc in the entire world, causing death to 60% of humans and 90% of reploids until Zero and X stopped them in the fourth year. This event has shaped most of Zero series' world and its characters, and yet info on the war are scarce. It is intentional - it was such a horrific war that the Neo Arcadian government, built after the war, decided to bury all historical texts and infos about the war deep in the ground, and declare anybody who knows it a Maverick, out of fear that "Weil's Sin" will repeat.
* ''{{RuneScape}}'' has the God Wars which had raged on for 4000 years, making up the entirety of the Third Age. Despite ending 2169 years ago, the repercussions are still felt today: many races are driven to extinction, down to LastOfHisKind or is a DyingRace; the gods are forced to depart from Gielinor. Many quests focus on this time: the Cave goblin-dwarf railway is postponed due to the discovery of related artifacts, the player rediscovers the myriad, a DyingRace of EnergyBeings, human-vampyre tension runs high but if another war breaks out, [[AllPowerfulBystander Guthix]] would be reawakened to [[TheEndOfTheWorldAsWeKnowIt destroy the world and remake it]].[[spoiler: Except now he's dead.]]
* ''Franchise/{{Castlevania}}'' has "The Demon Castle War" in 1999 where modern-day soldiers attacked (and died; given the zombies) Dracula's Castle. This war also heralded Dracula's true and final death at the hands of Julius Belmont & Alucard. There is no game that covers this.
* ''{{Freelancer}}'' has the [[TheEmpire Coalition]] / [[TheAlliance Alliance]] war, the beginning of which was shown in ''{{Starlancer}}'' but which lasted for another century afterward and the winner is not the one the first game would indicate, as well as the 80 Years War between Rheinland and the [[NGOSuperpower GMG]].
* ''Franchise/{{Star Wars|Expanded Universe}} VideoGame/KnightsOfTheOldRepublic'' has the Mandalorian Wars. Much of the information about it is from allusions and AsYouKnow statements in the games, and lots of characters you run into in both games are war heroes or veterans from one side or the other.
** Its successor, ''VideoGame/StarWarsTheOldRepublic'', has a recent war between the Galactic Republic and the reborn Sith Empire. The war ended when the Empire sacked Coruscant, held it hostage, and demanded a peace treaty (for reasons that vary wildly depending on who you ask). The two powers have spent the intervening years in a very intense just-this-close-to-hot UsefulNotes/ColdWar.
* For the longest time, ''Franchise/StarCraft'' had the Guild Wars, which were referenced only in vague snippets as a civil war whose consequences still loomed over the Terran worlds. Fast forward many years, it's been more-or-less explained away with [[ExpandedUniverse tie-in literature]]. Still nothing in the games, but this series has always assumed you [[AllThereInTheManual did the reading first]].
* In ''Franchise/TheElderScrolls'' series there have been many wars in its backstory, but only four act as direct backdrops for main quests. The first was the War of the First Council (culminating in the Battle of Red Mountain), taking place thousands of years ago, which saw the disappearance of the Dwarves and the Tribunal's (plus [[BigBad Dagoth Ur's]]) rise to divinity, setting the stage for ''[[VideoGame/TheElderScrollsIIIMorrowind Morrowind]]''. The second was Tiber Septim's conquest of Tamriel, aided by ''[[VideoGame/TheElderScrollsIIDaggerfall Daggerfall]]'''s giant mecha MacGuffin, Numidium, the third was the War of Betony between Daggerfall and Sentinel, which led to King Lysandus' death (and therefore his haunting of Daggerfall, which led to the main character being sent to the region to investigate...) and the fourth was the Great War (Empire versus Aldmeri Dominion), which took place between ''[[VideoGame/TheElderScrollsIVOblivion Oblivion]]'' and ''[[VideoGame/TheElderScrollsVSkyrim Skyrim]]'', the aftermath of which sets up the entire civil war plotline.
** The {{backstory}} for ''[[VideoGame/TheElderScrollsIIIMorrowind Morrowind]]'' provides another example from the Elder Scrolls universe. The "War of the First Council" and "Battle of Red Mountain" thousands of years ago set the stage for the plot of the game. The devout, Daedra-worshipping Chimer and atheistic, scientific Dwemer came into conflict in the land now known as Morrowind. After years of fighting, they were [[EnemyMine forced to team up]] to drive out the invading [[ConflictKiller Nords]]. Their alliance remained under the leadership of Chimeri Lord Indoril Nerevar and Dwemer Dumac Dwarfking, known as the "first council." It was a time of great peace and prosperity for both races. However, the Dwemer DugTooDeep beneath Red Mountain and unearthed the Heart of Lorkhan, the [[GodIsDead creator god.]] Chief Tonal Architect, Lord Kagrenec, crafted tools to tap into the power of the heart, hoping to allow the Dwemer to [[AscendToAHigherPlaneOfExistence transcend mortality]]. The Chimer, seeing this as a blasphemy against the real gods in the Daedra, attempted to stop the Dwemer, reigniting their war. Forces led by Nerevar and Lord Voryn Dagoth infiltrated the Dwemer Red Mountain stronghold. [[RashomonStyle Exactly what happened next is up for intense debate]], but the Dwemer disappeared from existence, Nerevar was slain, Dagoth Ur and the Tribunal used the tools on the heart to [[AGodAmI achieve godhood]], and Azura cursed the Chimer with dark skin and red eyes, transforming them into the modern Dunmer.
* The battle with the quiskerians and the death of Phaeton in ''VideoGame/LegacyOfHeroes''.
* ''Franchise/MassEffect'' has several of them: the Rachni War that ravaged the galaxy some thousands of years ago, the Krogan Rebellions a thousand or so years before the current date, the Morning War between the quarians and the geth, the Skylian Blitz, and the First Contact War/Relay 314 Incident that was humanity's introduction to galactic society. Most of the wars happened very long ago, but occasionally you'll find a veteran of the Krogan Rebellions (either an asari or a krogan, due to their immense lifespans), and many older humans and turians still remember First Contact. Come ''VideoGame/MassEffect3'', Javik, a revived Prothean, will talk about a series of wars that both his people fought (i.e. the Metacon Wars) and other conflicts in his timeframe.
** There's also the war on Garvug mentioned by the Cerberus News Network, in which corporate mercenaries attempted to take over a krogan-controlled world, and the Second American Civil War, the details of which can be found during the "Stolen Memories" mission.
* ''VideoGame/CaveStory'': References are made several times to a war for control of [[ArtifactOfDoom the Demon Crown]]. It's implied that the protagonist and Curly Brace were combatants in this war, two of the few surviving soldiers from the army that massacred the Mimigas. [[spoiler:But that's ultimately revealed to be false when Curly regains her memories--she remembers fighting to destroy the Demon Crown, separate from any army, with the protagonist as her only ally.]]
* ''VideoGame/GuildWars'': Prophecies has the actual Guild Wars, Factions has the Tengu Wars, Nightfall has the war against Palawa Joko.
* ''VideoGame/CityOfHeroes'' has the first Rikti War in Primal Earth, and the [[EndOfTheWorldAsWeKnowIt Hamidon Wars]] in Praetorian Earth.
* VideoGame/MetalWolfChaos: The Arizona Conflict
* ''VideoGame/BlazBlue'': The First War of Magic, in which humans (including Hakumen, Jubei, Valkenhayn, and Terumi) fought against [[EldritchAbomination The Black Beast]]. Later, the Ikaruga Civil War, in which Jin became "The Hero of Ikaruga" by murdering Bang's lord.
* ''VideoGame/GuiltyGear'' has the Crusades, an apocalyptic conflict between humans and Gears, led by Justice. In some games you can play duels that happened back then.
* The Seven Hour War from ''VideoGame/HalfLife2''.
* In the ''GroundControl'' games: [[WorldWarIII World War 3]], the Independence Wars, the First Stellar War, the Terran-Viron conflict, most of the Second Stellar War. There are mentioned in a few brief lines in the [[AllThereInTheManual manual]].
* In the ''[[{{Earth 2150}} Earth]]'' series, we never get to see or read details about [[WorldWarThree World War 3]], only that it was a NuclearWar that destroyed all former nation-states. Only a few facts are known from before the war, mostly about the founding of the [[OneNationUnderCopyright Lunar Corporation]]. The game history starts after the war, with the creations of the [[{{Eagleland}} United Civilized States]] and the [[TheEmpire Eurasian Dynasty]].
* In ''NexusTheJupiterIncident'', the [[AIIsACrapshoot AI Wars]] are mentioned, but no details are given. Other conflicts not mentioned or mentioned/shown only briefly are the war between [[OneWorldOrder IASA]] and the [[MegaCorp megacorporations]], the [[TechnicalPacifist Vardrag]]-[[LizardFolk Gorg]] War, and the Noah-Gorg War prior to the events of the game.
* The Great Keyblade War in ''Franchise/KingdomHearts''. It took place long before any other point in the game's timeline and was fought between [[TheChosenMany hundreds, if not thousands]] of different Keyblade bearers, all for the right to form the ''ultimate'' weapon and take control of the CosmicKeystone. The result: the weapon was shattered, the great power hid itself, and barriers rose between the worlds to prevent easy travel. All that remains is an absolutely ''massive'' FieldOfBlades on an otherwise abandoned world.
* ''Franchise/TheLegendOfZelda'':
** ''VideoGame/TheLegendOfZeldaOcarinaOfTime'' has a vague recounting of a war which occurred before Link was born and led to the death of his mother, who left him in the care of the Great Deku Tree. It's implied that this was the war that led to the unification of Hyrule.
** ''VideoGame/TheLegendOfZeldaALinkToThePast'' talks about a war[[note]]set shortly after Ocarina of Time in a timeline where Link died before beating Ganon, according to [[AllThereInTheManual the timeline]][[/note]] known as the Imprisoning War in which the Knights of Hyrule fought to give the Seven Sages the opportunity to seal Ganon in the Sacred Realm. It also talks about an even earlier war[[note]]sometime after Skyward Sword but before Ocarina of Time[[/note]] which led to the Triforce being sealed in the Sacred Realm in the first place.
** ''VideoGame/TheLegendOfZeldaTwilightPrincess'' mentions a similar conflict, describing how an evil tribe of powerful sorcerers (known in {{Fanon}} as the Dark Interlopers) came so close to getting the Triforce that the Spirits of Light had to entrap them in the [[EldritchLocation Twilight Realm]], where they evolved into the Twili.
** ''VideoGame/TheLegendOfZeldaSkywardSword'' mentions an earlier conflict in which Hylia and her armies fought against armies of invading demons to keep the Triforce safe. In this case, the offscreen nature of the war is actually justified: in the early days of the war, the group from whose perspective we see were sent up into the sky on a FloatingContinent with the Triforce to keep both safe and out of reach of the war.
** ''VideoGame/TheLegendOfZeldaALinkBetweenWorlds'' treats the events of ''A Link to the Past'' as this. There is also [[spoiler:the war fought for the other Triforce in Lorule, very much like the one fought in Hyrule. ''Un''like Hyrule, they destroyed the Triforce to keep it from being anymore trouble, [[TheEndOfTheWorldAsWeKnowIt which ended up being a very big mistake]].]]
* At the start of ''MetroidPrime 3: Corruption'', a Federation technician mentions that he hasn't seen "that many fighters scrambled since the Literature/{{Horus|Heresy}} [[TabletopGame/{{Warhammer 40000}} Rebellion]]".
* ''VideoGame/{{Fallout}}'' has the Great War, a two-hour war during which every nuclear-capable country in the world launched. No one knows who launched first.
** Two sources - the leader of the Enclave (the remnants of the US government) and the log of a Chinese submarine commander during the Great War - point to the Chinese. Still, they might be mistaken, and part of the lead-up to the Great War is still undetailed - the war between China and the USA have been given a fair bit of attention, but the other Resource Wars - especially the one between Europe and the Middle East, and the ones that happened in Europe after that - are still mostly names, if even that.
*** Also the theory that a bored AI started it.
** Kinda adverted with ''Fallout 3'' with the "Operation Anchorage" simulation, where you (virtually) fight a small part of the war to reclaim Alaska from the Chinese before the bombs dropped, though notes around the facility record that the simulation has been repeatedly rewritten at the orders of a general, and bears less and less relation to the reality.
* Loghain of ''VideoGame/DragonAgeOrigins'' often mentions the Ferelden rebellion against Orlais. Vague references to the war between the Qunari and the Tevinter Imperium are also present.
** The First Blight lasted 192 years, the Second lasted 90 years: the Third and Fourth blight were comparatively smaller and lasted only 15 and 12 years. At the beginning of ''Origins'', Duncan is desperatly trying to increase the ranks of the Fereldan Grey Wardens in order to avoid another Blight lasting years or even generations. [[spoiler:''VideoGame/DragonAgeII'' confirms that the Fifth Blight, which is the setting of ''Origins'', lasted a full year, which is comparatively amazing.]]
** The plot of ''VideoGame/DragonAgeII'' is about what ''started'' the Mage-Templar War that has engulfed all of Thedas by 9:40 Dragon. Vague hints are all we actually know about the present in which the framing-device is set in, whereas the game itself focuses on the life of Hawke from 9:30 - 9:37 Dragon and how the Champion came to unintentionally participate in the opening shots of the conflict.
** Thedas history is built on one enormous war after another. The titular Dragon Age was predicted to be a time of upheaval, but it's still got some catching up to do in terms of body count. The oldest known conflict, predating the First Blight and the Age system, is the elf empire vs the nascent [[TheMagocracy Tevinter Imperium]]. The sheer loss of elf culture is still being felt centuries later.
** The novel ''Literature/TheStolenThrone'' describes the rebellion against the Orlesian occupation, although the final battle in which Loghain really proved himself as a general is not described (the future King Maric wasn't even present there, choosing instead to settle a personal score).
** ''Videogame/DragonAgeInquisition'' reveals some important info about the war between the Elven empire and Tevinter [[spoiler: - namely that the elves were already involved in a ''civil'' war. Far from the mighty conquerors their descendants imagine, Tevinter was kicking the elves when they were already down.]]
* The First Eptinan Wars exist has only a blurb in the manual for ''VideoGame/VanguardBandits''. The Second, also has this effect, having been going on since before the game starts, and despite still going on most of the backstory for it exists in a single flashback.
* SquareEnix seems to love this trope:
** ''VideoGame/FinalFantasyVI'': The War of The Magi that destroyed previous civilization(s) and petrified the Warring Triad, goddesses of magic.
** ''VideoGame/FinalFantasyVII'': The war in which Shinra conquered the world, especially Wutai. The very end of this war (the conquest of Wutai part) is the very first chapter of ''CrisisCore''.
** ''VideoGame/FinalFantasyVIII'': The war between Galbadia and Esthar, roughly eighteen years before the game began, which was caused by Sorceress Adel, the ruler of Esthar, attempting to TakeOverTheWorld.
** ''VideoGame/FinalFantasyX'': The war that destroyed the world and drove [[BiggerBad Yu Yevon]] mad, turning him into a mindless summoner.
** ''VideoGame/FinalFantasyXI'': The stage is set by the great Crystal War of twenty years earlier; the opening cinematic shows a climactic battle from the War. The three great cities now deputize adventurers because of how the war depleted their armies. Becomes an onscreen war in the Wings of the Goddess expansion, where characters can travel back in time and participate in the war.
** ''VideoGame/FinalFantasyXIII'': The War of Transgression, which nearly destroyed Cocoon 500 years ago.
** ''VideoGame/FinalFantasyXIV'': For ''A Realm Reborn'' players, the United Eorzea-Garlemald war that culminated in the Battle of Carteneau is this, with the current conflict being an extension of it. ''Legacy'' players got to experience it firsthand.
** ''VideoGame/FinalFantasyTactics'': The war fought between Murond and the Zodiac Braves. [[spoiler:The truth is very different from what scholars accepted as historical facts.]] And recently, the 50 Year War in which many of the game's older famous generals made a name for themselves.
** ''VideoGame/DissidiaFinalFantasy'': The war between Lufenian and their neighbor, which facilitated the birth of [[BigBad Chaos]] to defeat Omega.
* ''VideoGame/{{Touhou}}'': The Great Suwa War, in which Kanako subjugated Suwako; and Yukari's (first) invasion of the Moon. [[spoiler:''Silent Sinner in Blue'' is essentially Yukari making revenge upon the Lunarians over her defeat 1,000 years ago.]]
* The Belkan War was this in ''VideoGame/AceCombat5TheUnsungWar'': the only events mentioned in the game were that Bartlett and Pops were shot down together, and that it ended when Belka dropped seven nukes on its own soil. It was later expanded on in ''VideoGame/AceCombatZeroTheBelkanWar''.
* Since ''VideoGame/GrandTheftAutoIII'' radio conversations and ads have hinted at a war between America and Australia which happened sometime in the mid 1980s. It's played for laughs.
* ''VideoGame/SepterraCore''. The Resource Wars, the most recent of the wars between Ankara and Jinam. Also the war between Chosen factions that devastated Maya's hometown.
* The Ura-Caelondia war in VideoGame/{{Bastion}}. It's been over for a while, but a lot of the Ura and the only living Caelondian old enough to remember it (Rucks) are still a bit sore over it.
* ''VideoGame/TalesOfVesperia'' references The Great War between humans and Entelexeia. One of the party members is a veteran.
* The ''FireEmblemElibe'' games (being the 6th and 7th titles) had a great war between humans and dragons, referred to as 'The Scouring' that occurred roughly 1000 years before the events of the games. It ended with the humans supposedly killing off the dragons, when, in actuality, the dragons, on the verge of defeat, exiled themselves to the land of Arcadia, closing the gate portal behind them.
** Most FireEmblem games have this as a part of the backstory. The Archaneia games have the first war against Medeus and the dragon-realm of Doluna, where Marth's distant ancestor won fame for sealing the dragon away. Fire Emblem 8 details an ancient war against the Demon King, where the Five Heroes and the Manaketes defeated the demons, then went on to found the current kingdoms of the realm (sans Carcino). The Tellius games give us several offscreen wars of the past, the biggest being the ancient OrderVersusChaos war between Ashera and Yune, with various factions siding with either goddess. There was also a great revolt of Laguz to liberate themselves from Begnion slavery.
** ''VideoGame/FireEmblemAwakening'' has one occuring just one generation before the game, instigated by the previous exalt of Ylisse and causing tension with neighboring countries, as well as one [[spoiler:In the future, specifically the war between Plegia and Ylisse having been elongated in the previous timeline and extending well into the childhoods of the second generation characters and eventually leading up to a ZombieApocalypse that destroys the world, forcing them to travel back in time.]]
* In ''VideoGame/UltimaVI'', there's supposedly a huge war with the gargoyles going on. The soldiers talk about it. You see the wounded being cared for in Cove... however due to the WideOpenSandbox gameplay you travel all over the fairly pristine world and never find a single battleground.
* ''VideoGame/DungeonsOfDredmor'' contains many references to a war between elves and dwarves that's taken place back on the surface; the dungeons are full of discarded weaponry and such.
* ''ArTonelico'' series: the thousand-year war between Sol Ciel and Sol Cluster that peaked with the [[TheEndOfTheWorldAsWeKnowIt Grathnode Inferia]]. Only a few people actually remember the events of it by virtue of being over 700 years old.
** ''ArTonelico 1'' has the war between Mir-led Reyvateil and humans, which ended with Mir sealed and the Reyvateil treated as second- or even third-class citizens.
** ''ArTonelico2'' has the previous period of conflict between the [[RageAgainstTheHeavens Grand Bell]] and the [[AssimilationPlot Sacred Army]]. The current period of conflict takes the majority of the gameplay, so it doesn't feel very offscreen-y.
* The ''Franchise/AssassinsCreed'' series makes reference to a war that occurred tens of thousands of years ago in the First Civilization, between [[{{Precursors}} Those Who Came Before]] and the humans they used as slaves. This war is never detailed, but is instead used as a context to explain how the {{Half Human Hybrid}}s "Adam and Eve" became {{Phlebotinum Rebel}}s and stole the secret of the [[MacGuffin Pieces of Eden]]. And then their civilization was wiped out by a [[CozyCatastrophe solar flare]], making the whole thing moot.
* ''VideoGame/{{Hexx}}'' mentions the Chaos wars, which apparently involved one of the four deities in the setting.
* The ''[[VideoGame/{{X}} X-Universe]]'' backstory includes the [[RobotWar Terraformer War]] in the 2140s AD, during which [[AIIsACrapshoot insane terraforming robots]] wiped out all of Earth's extrasolar colonies and nearly destroyed Earth, too. A Terran warfleet managed to lure them through a jumpgate, which was then destroyed behind them; this fleet became the Argon race. About 200 years later, we had the [[ First Xenon Conflict]], where the terraformers reappeared, followed by the [[ Boron Campaign]], a more conventional interstellar war between the various superpowers.
* Lt. Surge in ''VideoGame/PokemonRedAndBlue'' refers to a war in which his electric Pokémon "zapped [his] enemies into paralysis." None of the subsequent games (except the [[VideoGameRemake remakes]], which repeated the line exactly) mentioned anything about this war.
** A popular fan [[ theory]] theoriezes that there was a large conflict before the first game, which is why there are so few adult males; most are either older, or children.
* A war three-thousand years before ''VideoGame/PokemonXAndY'' serves as the backstory for the game's plot.
* ''VideoGame/{{Xenoblade}} Chronicles'''s ActionPrologue is the Battle of Sword Valley, which was the last battle of the Mechon invasion of Bionis and where [[DecoyProtagonist Dunban]] became a legend throughout the land for singlehandedly turning back the enemy advance.
* ''VideoGame/TheLastStory'' had a war that occurred hundreds of years ago that was ended by House Arganan. Later on, another large war engulfed the Empire that killed the families of Zael and Dagran, which led to them becoming mercenaries. In addition to ''that'', it is also stated that the Empire has fought many campaigns against the Gurak people in the past. The game's plot is well and truly kicked off when the Gurak invade Lazulis Island, sparking off another war.
* ''VideoGame/PandorasTower'' has a war that occurred fifty years ago. Unlike most instances of this trope, this particular war and its fallout have [[CataclysmBackstory great plot significance.]] Later on, the kingdoms of Elyria and Athos had been fighting a war that ended only two years before the game begins, and tensions between the two countries are still high despite the peace.
* ''GearsOfWar'' has the Pendulum Wars, which is where Marcus Fenix made himself a war hero. And the majority of the Locust war that happens before the first game opens.
* ''VideoGame/MightAndMagic'' and ''VideoGame/HeroesOfMightAndMagic'' (old verse) have the Timber Wars between Erathia and [=AvLee=] over the Contested Lands. Some hero descriptions mentions them, they're a key part of the backstory for ''VII'' and one campaign in ''Heroes III''... and the only one we get any real detail is canonically not a proper war (''VII'' involves a renewed conflict over part of the Contested Lands, but the only things that are ''assured'' to happen in the conflict are skirmishes and manouevering for position, followed by peace negotiations. It can escalate into a full-scale war, but hints in later games implies that the path in which that occurs isn't the one that happened).
* In ''Franchise/{{Halo}}'', meanwhile, there's the small offscreen war. There was a civil war in between two factions of Humanity, which is what the Spartans were made for. A little of this is shown in the novelizations. It was replaced by the great ONSCREEN war with the Covenant.
* Buried in the backstory to ''VisualNovel/HatofulBoyfriend'' is the war between humans [[GenocideBackfire and]] just-[[UpliftedAnimal uplifted]] birds, which started with the disorganized Hitchcock Winter, became formal when birds drew up their own Declaration of Independence, and continued for thirty years until humans surrendered. [[spoiler: Of course things aren't entirely peaceful now...]]
* The Solar Alliance-New Empire war in ''VisualNovel/{{Sunrider}}'', which led to the rise of PACT.
* ''VideoGame/WorldOfWarcraft'' 's ExpandedUniverse has golbins mention in passing a series of no less than four Trade Wars, and described as worse, the [[RuleOfFunny Peace War]]. Details are sparse, limited to battles having been fought in the tunnels of the goblin capital Undermine, and [[ArsonMurderAndJaywalking Trade Prince Gallywix's favorite bakery being repeatedly destroyed over the multiple wars.]]
* In ''{{VideoGame/Warframe}}'', The Old War between the precursor Orokin Empire and the Sentients is pretty much the cause of the state of present setting. It was the cause of the creation of the playable faction, the Tenno, the release of the [[ZombieApocalypse Technocyte Plague]], and if the Stalker is to be believed, indirectly resulted in their destruction when [[spoiler:the Tenno TurnedAgainstTheirMasters and]] destroyed them, leaving behind the reams of LostTechnology that everyone is squabbling over now.
* ''VideoGame/NosferatuTheWrathOfMalachi'': The Scripts Of Grimvald Vorius mention that [[spoiler:Malachi was sealed away]] after an event known as "the Crimson Wars" centuries ago.
* The [[NoodleIncident "Great Mistake"]] in ''VideoGame/CivilizationBeyondEarth'' is sometimes implied to have been WorldWar3, or a regional nuclear exchange (India and Pakistan are often brought up in this context). Other times it seems that it was an ecological collapse and/or some kind of unexplained science [[GoneHorriblyWrong going horribly wrong]] -- whatever it was, it's the cause of EarthThatUsedToBeBetter.
** Likewise, in ''Beyond Earth'''s spiritual predecessor, ''VideoGame/SidMeiersAlphaCentauri'', had [[spoiler:the implication that civilization back on Earth completely went to shit not long after the ''Unity'' left. By the time Planet's descendants finally return to their world of origin, Earth is a lifeless rock with a few giant craters in it]].
* Though it's only [[JigsawPlot hinted at]] until the sequel, before the events of ''VideoGame/HotlineMiami'', [[spoiler:the Soviets attempted to invade America, managed to make it at least to occupying Hawaii and nuked San Francisco]].
* ''VideoGame/{{Splatoon}}'' has the Great Turf War between the Inklings and Octarians that took place a century before the game's events, in which the Inklings ended as victors. MissionControl Cap'n Cuttlefish was part of this war, and several of its details are revealed in a few of the [[StoryBreadcrumbs Sunken Scrolls]] hidden through the single player campaign.

[[folder:Web Comics]]
* One (probably two) of the four "Breakings" from ''TheDragonDoctors''.
* The war with the Other in ''Webcomic/GirlGenius'' occurred about twenty years before the events of the comic, and was basically a Steampunk zombie apocalypse. Then, after the Other's unexplained disappearance, the surviving Sparks and nobles immediately started fighting over what was left. [[ Klaus put a stop to all that.]]
* ''Webcomic/RoninGalaxy'': Taylor speaks to Cecil about the current war-like state of Earth and her difficulty getting to the Moon [[ on this page.]] Cecil retorts that Earth is an "antique collecting space dust."
* The Teraport Wars from ''Webcomic/SchlockMercenary'' count. Although its pretty easy to imagine the effects the Teraport would have on a galaxy used to wormgate travel for war and trading, we never actually see much of the chaos the invention actually inflicts on galactic civilization apart from a single battle.
* The Old War in ''SkinHorse'' has been mentioned a few times. Tip has no idea what it was, and finds it very hard to get details from the nonhuman community, either because [[ a crisis is going on]], or because [[ they don't actually know anything]].
* There are several of these in ''{{Drowtales}}'', including several wars of the Surface between the Dark and Light Elves and the conflict that eventually led to the Surface becoming uninhabitable, forcing the remaining elves to flee underground. Then there's the war between the Dark Elves and their children, the Drow, which led to the near extinction of the Dark Elves. The city of Chel'el'sussoloth also has a few of these such as the Sharen vs. the Sullisin'rune and various other times the Imperial forces have come into conflict with rogue clans.
* ''Webcomic/HowToRaiseYourTeenageDragon ''references the Nephilim War, an invasion of the friendly furry kingdom Xootopia.
* ''WebComic/OnlyHuman'' has Luna War I and Luna War II, which eventually brought the end of human civilization.
* ''WebComic/GeneCatlow'': There was some sort of armed conflict that led to the Animen being granted full civil rights and several older supporting characters were a part of it. But it's never been spelled out whether this was a full-on revolution, an "Arab Spring" type uprising or a touchstone event like the Stonewall Riots.
* ''Webcomic/SisterClaire'' has a war between the Witches and the Nuns about 20 years ago that greatly affected the world, including causing bits of the landscape to be missing, and the after effects still linger among the characters, several of whom were on either side, including [[spoiler:Catharine's sister Clementine, who was the leader of the Witches known as The Bright One]].

[[folder:Web Original]]
* In the ''WebVideo/NatOneProductions'' universe of ''Denazra'', this trope has been going on for hundreds of years. The titular [[AIIsaCrapShoot denazra]] have been conquering our tiny slice of the galaxy over the course of many generations. Most recently, the [[TheAlliance Coalition]] was completely routed at Orm.
* ''Machinima/RedVsBlue'' (especially the ''Recollection Trilogy'') makes repeated references to some kind of great war against an alien race. The only details are that it took place during ''The Blood Gulch Chronicles'' and was resolved offscreen sometime between ''Blood Gulch'' and ''Reconstruction'' (or possibly sometime before the end of ''Blood Gulch''), that Project Freelancer was one of many desperate initiatives towards the end of the war, and that humanity became allied with the aliens afterwards. The war occasionally seems to intrude on the Reds and Blues in Blood Gulch [[spoiler: but it's unclear if those events were genuine, or just training scenarios for Tex.]]
** Another possibility is that the war they mentioned is an attempt by Rooster Teeth to put the series into the Halo continuity. One example is the mention that the Freelancer-project was just one of the magic bullets created to win the war since the war was going really bad for the humans possibly referencing the different projects (for example Spartan II and III) during the covenant war. More can be read on the Red vs Blue [[ WMG page]]
* The [[WesternAnimation/MyLittlePonyFriendshipIsMagic My Little Pony]] spoof series FriendshipIsWitchcraft features this in the second episode, [[ "Read it and Sleep"]], with [[LadyOfWar Rarity]] admitting that she is still [[AlternateCharacterInterpretation traumatized]] after The War.
** The War is referenced again in episode 7, "Cherry Bomb", where Applejack's blue ribbons (from the episode [[Recap/MyLittlePonyFriendshipIsMagicS2E14TheLastRoundup "The Last Roundup"]]) are portrayed as being medals from The War.
* Salad Fingers from ''SaladFingers'' often references an event called the Great War in a few episodes. However, it's so far unknown if the war was nuclear or even existed at all as it could be all in Salad Finger's mind.
* ''WebAnimation/{{RWBY}}'' mentions a few distant wars.
** Once upon a time, humans were driven to the brink of extinction by the Grimm. Humanity discovered the power of Dust and fought back, eventually gaining enough territory to build several kingdoms.
** Eighty years ago, some corrupt leaders attempted to stamp out individuality and artistic expression. The people fought back and ended their campaign.
** The [[LittleBitBeastly Faunus]] fought back when the kingdoms tried to force them to live in [[FantasticGhetto the town of Menagerie]]. After some decisive victories, they won the right to live alongside humanity, though there is still a lot of discrimination.
* Several previous conflicts are mentioned in ''Literature/TheSolsticeWar'' but only the Ayvartan Civil War and the Nocht Unification War have been explored the tiniest bit in the story (through short flashbacks). At one point a character has a flashback of a dozen conflicts, suggesting a long history of Great Off-Screen Wars.

[[folder:Western Animation]]
* {{Franchise/Transformers}}: Has this to varying degrees, the Cartoon itself is a straight example, as the war has restarted on Earth and the million year war on Cybertron is only alluded to.
** The war between the Autobots and the Decepticons in ''WesternAnimation/TransformersAnimated''. By the time the series starts, the war is over, with the Autobots having won and the Decepticons scattered to the far reaches of space.
** The first flashback material was repurposed clips from ''WesternAnimation/TheTransformers Generation One''. We later see some flashbacks from Ratchet's perspective.
** Speaking of ''Franchise/TransformersGeneration1'', it contains references to the Third and Fourth Great (or "Cybertronian") Wars, the assumption being that there were a first and second. (They're probably in the fourth one. Or the fifth, if you consider the ending of ''TransformersTheMovie'' to be the end of that particular war.)
** And speaking of ''Transformers: The Movie'', the movie was never seen in Japan until four years after its American release, and even then Japanese fans have already seen Season 3 (there called ''Transformers 2010''). As such, events from the movie were referred to but ''never'' seen. So this would count, as it had gained a mysterious and legendary quality beforehand. Japanese first coined the term the "Unicron War".
** In the Generation 1 episode "Sea Change", Perceptor mentions a "Third Cybertron War". Apparently separate from the Third Cybertron'''ian''' War. Though given the context, it's not clear.
* ''{{SonicSatAM}}'' has a briefly-mentioned "Great War". [[BigBad Robotnik]] had put himself into a position to take over by [[NoodleIncident helping Mobotropolis win it.]]
* Not ''exactly'' a war, but ''WesternAnimation/AvatarTheLastAirbender'' has the Fire Nation's destruction of the Air Nomads 100 years prior to the start of the series.
** The War itself is an an interesting variation in the show. We know why it started (the Fire Nation got all expansionist), when it started (100 years previous), who is fighting it (Fire Nation vs Earth Kingdom and the Water Tribes), and the characters are fighting its final year. However, we only get, at most, a couple flashbacks over 61 episodes. We don't see many battles even during the present (three, ''maybe'' four if you count "The Drill"). In fact, the entire century of conflict between Aang's freezing to when Katara frees him is mostly untouched even in fan fiction.
* According to WordOfGod, ''WesternAnimation/AdventureTime'' takes place after "The [[EverythingMakesAMushroom Mushroom]] War", which pretty much destroyed all of humanity.
** Also notable is the war between rainicorns and dogs, which is never elaborated upon (beyond mention of Lady Rainicorn's father being saved by a dog at some point during it) but shown as a cause for great strife between the species.
** The Mushroom War has since been elaborated upon, very slightly, in the episodes "Finn the Human" and "Jake the Dog." They seem to have begun with a fleet of bombers, one of which dropped a bomb that [[spoiler: unleashed massive mutagenic, likely magical, energies, and these energies either gave birth to the Lich or revived him in the then-modern world.]] What happens after that is entirely up to speculation, although shots of the current "Earth" from space in a few episodes show that about a third of the planet was simply blown away.
* ''WesternAnimation/BatmanBeyond'' referred occasionally to "The Near-Apocalypse of '09," wherein the Justice League managed to seemingly kill the notoriously unkillable Ra's Al Ghul for good. Its nature has been speculated on for years by {{DCAU}} fans; one guess is that the final battle of ''[[WesternAnimation/JusticeLeague Justice League/ Unlimited]]'', which was definitely a "near-apocalypse," but the instigator of that conflict was Darkseid, not Al Ghul.
* ''WesternAnimation/{{Futurama}}'' occasionally makes reference to some war or another, usually for a quick gag. The one time one is relevant to the main plot is in "Three Hundred Big Boys", where the spoils from a recently-won BugWar are spread among the populace.
* The ''WesternAnimation/SpongebobSquarepants'' episode of the Krusty Krabs employment video stated that Mr. Krabs created the restaurant some time "after the war".
* The Crystal Gems of ''WesternAnimation/StevenUniverse'' fought in a war with the other Gems over protecting or exploiting the Earth, and are still dealing with the fallout, over 5000 years later. Currently, the Crystal Gems are terrified by the possibility of that war starting again.
* The [[ArtificialHuman Neosapien]] [[TurnedAgainstTheirMasters Rebellion]] a.k.a. the First Neosapien War fifty years ago in ''WesternAnimation/ExoSquad''. It is particularly oft mentioned in the early episodes, before the ''Second'' Neosapien War breaks out and easily surpasses the original one in scope and impact.