"There was a time when this whole quadrant belonged to us! What are we now? Twelve worlds and a thousand monuments to past glories. Living off memories and stories, and selling trinkets. My god, man! We've become a tourist attraction. 'See the great Centauri Republic - open 9 to 5 - Earth time.'"
In Lyrical Nanoha, Ancient Belka was a powerful empire that spanned many dimensions, a mighty civilization that conquered every world that came its way with its superior magic and technology. However, infighting mixed with the Lensman Arms Race and widespread pollution have destroyed the empire from the inside until it finally fell apart after the self-sacrifice of the last Saint King, Olivie Segbrecht. All that's left of the Belkan Empire in modern times is the Saint Church Autonomous Region in the Northern Mid-Childa, although the Saint Church focuses more on the religious than political power (their doctrine is based around Olivie as the messianic figure) and preservation of the Ancient Belkan cultural and magical heritage. Setting a number of nuclear bombs off on themselves didn't help.
The Anglo-Saxon Kingdom in Britain during Vinland Saga, being constantly invaded by various Norsemen. Askeladd even discusses this with Thorfinn, bringing up the Roman Empire and all it's glory and advancement that led it ultimately into destruction, saying that it is the same now for the Kingdom of the British who contributed to the Roman downfall. Neatly enough, Thorfinn chucks away a Roman coin he picked up in the ruins (naturally Roman) they were standing in, since it was worthless to him.
The Earth Federation from the Universal Century universe of Gundam is this, in a pattern that echoes Gibbon's Decline and Fall. The Federation won the One Year War in Mobile Suit Gundam through superior power and production capability, but at the cost of half of the world's population. Seven years later, in Mobile Suit Zeta Gundam the Earth Federation has weakened to the point that the remnants of Zeon are still a serious threat, and a State Sec organization is intentionally sabotaging the Federation from within so that they can take over. Afterwards, in Char's Counterattack, even though Zeon has been defeated twice already, the Earth Federation is so weak that the Neo-Zeon nearly make the Earth uninhabitable and only a miracle caused by Amuro's death stops it. By the time of Victory Gundam (60 years after CCA), the Federation is so weak and ineffectual that it falls to a militia to oppose The Empire. Despite all of this, however, the Earth Federation is the eventual victor in each of these conflicts, if only through outlasting the various threats to its survival. If the live-action film G-Saviour is canon, then the Federation finally collapses around UC 200, when the Colonies finally achieve independence and form a new government together with the Earth, but this time with the Colonies (renamed "Settlements") as equal diplomatic partners. Not that this new government is any better than the Federation ever was.
In Axis Powers Hetalia, the now dead countries of Ancient Greece, Ancient Egypt, Rome, and Germania play this role, with Rome being the prominent one. He left two (idiotic) grandsons behind who are constantly being fought over because of their grandfather's inheritance, Germania is the father/grandfather of the Holy Roman Empire, Germany, and Prussia, and Ancient Greece and Egypt each left behind a son who spend a great deal of time discovering and researching the ruins of their mothers' kingdoms. Rome even comes back from heaven occasionally to check up on N. Italy and bother Germany. And if history's any indication, this may apply to Austria as well, who, as both the Austrian Empire and (one half) of Austria-Hungary, served as a remnant of the Holy Roman Empire.
In the Gene Catlow fanfic The Basalt City Chronicles, the Empire of Smilodons once ruled an empire spanning from Burma in the southwest and Chile in the southeast, to the Bering Strait in the north. They're now down to a group of islands in the Bering Strait, though they've still got plenty of their ancient national treasure...
In the 1983: Doomsday Stories for Axis Powers Hetalia, there are nods to Austria still feeling this despite being one of the core members of the Alpine Confederation, though with painful justification. Having been reduced to a neutral Cold War buffer by the time Doomsday came, he was powerless to stop the bloodshed and save Hungary, which would come to haunt him in the years to come.
The Galactic Empire from Isaac Asimov's Foundation novels turns into this over the course of the series, and the Roman parallels are many and explicit, including a Justinian-like reconquest that collapses in on itself. By the time of the Mule, the Empire controls only twenty agricultural worlds, having abandoned its original capital planet of Trantor after the Great Sack. When the story's protagonists visit Neotrantor, the new capital, the senile Emperor is under the impression that the Empire is as strong as ever, treating the Foundation as just another world within the Anacreon Province of the Empire.
A slightly odd example which nonetheless fits all the above criteria is the U.S. government in Snow Crash, although in this case the "cutthroat politics" are office politics between software engineers. Power, influence and respect all withered away, so they fill the void with bureaucracy.
Gondor from The Lord of the Rings has been in decline for the past one and a half thousand years, with its throne vacant, its borderlands constantly threatened by invasion, its former capital reduced to a Ghost City, and the White Tree dead. Its sister kingdom Arnor went through a centuries-long decline in the backstory until its last remnant, Arthedain, was entirely destroyed. This reinforces the parallelism with the ancient Roman empire: one part (Arnor = Western Roman Empire) has collapsed under attack, the other (Gondor = Byzantine Empire) subsists as a beacon of civilization built around a borderline impregnable city (Minas Tirith = Constantinople), but is shrinking and weakened by devious politics. In a bit of a subversion, the appendices cite that after the War of the Ring, Gondor grew back into power under King Elessar (Aragorn), a descendant of the kings of Arnor and Arthedain. An alliance with Rohan led by Éomer also sturdied the emerging Dominion of Men (including Arnor's old lands) as well. Where this re-emergence of power goes following Elessar's death at the end of the appendices' timeline, no one is certain.
The Elves of Middle Earth also qualify, having been the dominant race of Middle Earth prior to the wars against the forces of darkness (Morgoth and later Sauron) and the rise of men resulted in them diminishing in both number and power.
Ergoth in the Dragonlance books. Solamnia too, though its decline is eventually reversed.
The post-Endor Empire is like this, getting progressively more so as time passes. Various defeats actually led to factions led by formerly-Imperial warlords splintering off. Now and again it surges back somewhat, like under Grand Admiral Thrawn or the Emperor Reborn, but since the people behind these surges are inevitably killed, these are temporary. The one good thing Daala did was to reunite the forces under the warlords; she promptly killed off a good portion, but she did leave the still-united remains in the command of someone who knew their limits. By the time of the Hand of Thrawn duology, the weary Supreme Commander looks at the eight sectors and thousand systems they still command, the two hundred Imperial Star Destroyers, the "Preybird" class fighters they buy from he knows not where, and thinks about how the Empire once ruled a million systems, had twenty-five thousand Star Destroyers, and could afford more than one surviving major shipyard which couldn't keep up the demand for capital ships, let alone starfighters. He believes that the only way it can survive is for him to make peace with the New Republic. And he does. When, while pushing for the Moff Council to support his peace treaty, he's told that the Empire still has significant military power, Pellaeon's response is that they have just enough power for the New Republic to consider them worth destroying if peace is not achieved. Fittingly, this territory is called the Imperial Remnant by the rest of the Galaxy.
Tolnedra from the Belgariad (Although most of the countries around it were never really under its political influence, they still act as if they controlled the whole continent once upon a time). They are a greater force for law and order in large portions of Arendia than the Arendians are, and the backstory details how they basically forced the other countries to create Sendaria at one point.
Ankh-Morpork is a rare example of a Vestigial Empire where main characters not only come from the corrupt and decadent city, but often spend the entire book there. Also notable in that while the actual empire is long gone, and the Patrician expresses distaste with recreating the idea ("We are not having another Ankh-Morpork empire; we've only just got over the last one"), the Pax Morporkia is still in effect in many places due to Ankh-Morpork's economic and cultural dominance, only now instead of 'Do not fight, or we will kill you' it is 'Do not fight, or we will call in your mortgages.' In this case, the closest historical parallel would probably be London.
Another example from Discworld would be Djelibeybi, Pratchett's analogue to Ancient Egypt in Pyramids. They only control a tiny stretch of river by the events of the book, but it's stated that they used to control most of the continent before they sold it all to pay for pyramids.
In S.M. Stirling's novel In the Courts of the Crimson Kings, the Tollamune emperors once ruled all of Mars. By the time of the story they are reduced to ruling the territory around their capital at Olympus Mons, where all the old court officials and functionaries continue, though largely without actual functions.
Almost every nation in The Wheel of Time is this, at least on the continent where most of the story takes place, due to a mysterious depopulation and the effects of repeated wars. Even the tiny city-state of Mayene claims to be ruled by a descendant of Artur Hawkwing's continent-spanning realm, and there were entire kingdoms swallowed by the Blight that were supposed to be very strong. Much of the depopulation since then could be attributed to people being killed/enslaved by raiding from the Blight. All of the major southern cities are indicated to be very large, as they have never been attacked and some (at the beginning of the series, at any rate) did not even believe that Trollocs existed.
In Fritz Leiber's Fafhrd and the Gray Mouser series, Quarmall used to be a large kingdom, but by the time the eponymous pair see it, it's a single city that's almost all underground.
Likewise Lankhmar itself; in The Swords of Lankhmar, Kreeshkra mentions that "Lankhmar's empire stretched from Quarmall to the Trollstep Mountains and from Earth's End to the Sea of Monsters".
The Commonwealth in Book of the New Sun claims to be the successor state to the monarch's interplanetary empire, but in actual fact they only control part of one continent on Earth. Still, the interplanetary civilization recognizes the Autarchs of the Commonwealth as the legitimate spokesmen for Earth, which drives the entire plot ofThe Urth of the New Sun. Bonus points because the Commonwealth is an Expy of the Byzantine Empire in South America.
Kull's kingdom (Valusia, part of said Thurian civilization) is also this. He is told he can restore some of its lost glories.
By Conan's time there are a few as well, such as Stygia (Ancient Egypt but filled with shadowy evil) and arguably Koth (The Roman Empire, but with less of the "powerful, disciplined legions" part and more of the "ludicrously decadent rulers" part). Then there is dreaded Acheron, which, despite having been destroyed almost three millenia ago, has left remnants that are still deadly to those unlucky of stupid enough to stumble on them, as ''The Hour of the Dragon" demonstrates.
The Strugatsky Brothers' Hard to Be a God is set in one of those - significant portions of the the empire are independent states in all of the ways that matter, something which the Imperial nobility loathes to acknowledge.
The Empire of Humanity gradually becomes this during the course of Sergey Lukyanenko's Genome trilogy, transforming from a strong star-faring empire to a weak shadow of its former self.
The Taii to an even greater extent. Once rulers of most of known space, they have been reduced to a few dozen worlds and are hopelessly behind the younger races which have arisen after the Taii Empire's collapse. Unlike the human example, the current state of the Taii is due to a devastating interstellar war fought against an equal galactic power. As the author maintains, such a conflict will inevitably result in the destruction of one of the powers and a Pyrrhic Victory for the other, for it will have lost much in the war. The once-mighty moon-sized Taii battleships still patrol much of what used to be theirs. However, this is only because the current rulers of that space allow the Taii this small favor as a testament to their former glory. Those battleships are escorted by modern warships a tiny fraction of their size but which can blast the massive Taii relics with a single volley. The author uses this as a clear example of what will happen to humanity should they enter into a such a conflict with the Czygu, an equally strong empire.
Even moreso, if the human-Czygu war breaks out, the Emperor will be forced to lift the quarantine of Ebon, a world of religious fanatics who absolutely hate all aliens and have built up a massive war machine dedicated to eliminating all those who are not true children of God. This will cause all aliens to band together against the humans and result in mutual destruction of everyone involved. Anyone who remains will be a clear example of this trope.
In The Legends of Ethshar, Old Ethshar became this after a time. It once controlled a sizable continent to the south but the centuries of war against their enemy led to the original empire fracturing into dozens of squabbling countries, each claiming legitimate rule to the whole empire. The army fighting in the north decided to just use the newly captured lands to found a new nation rather than deal with that.
Subverted with the Fjordell Empire in Elantris. On a map, Fjorden appears to be only a shadow of its once continent-spanning might, but it's far from in decline. Rather, it's leaders recognized that attempting to millitarily reconquer their old lands would be unfeasible, and so made an alliance with the Shu-Dereth religion. The "new" Fjordell Empire fused its own political hierarchy with the Derethi religious hierarchy, and as a result it's actually far more powerful than it was in its heyday through the Derethi religious sphere of influence. Anyone who is politically aware in this world knows that Fjorden is far from the Vestigial Empire it appears as at first glance.
The Romulan Star Empire of the Star Trek universe seems destined to become this in all realities - note that this was even the case before its destruction in the 2009 film.
In the Star Trek Novel Verse, post Star Trek: Nemesis, the Star Empire fragmented into factions. Praetor Tal'aura and Proconsul Tomalak were able to reunite most of them, as the Federation sought to maintain peace along the borders (the Klingons "helped" by making Remus a protectorate). Commander Donatra, however, declared the worlds and fleets loyal to her independent. Between losing territory to Donatra, uprisings on the outworlds, and the damage from the Borg Invasion, the Empire was less than half its former size. It was explicitly stated in Star Trek: Articles of the Federation that the Romulans were no longer a superpower. They bounced back thanks to membership inthe Typhon Pact...only for the empire to presumably collapse again when Romulus was destroyed (though we're still a few years short of that in the current timeframe...)
In Star Trek: Mirror Universe, it happens sooner, after Romulus is destroyed early by a weapon of mass destruction. The core forces of the empire are reduced to joining forces with anti-Alliance freedom fighters in order to survive. The Star Empire is restored towards the end of Rise Like Lions following the collapse of the Alliance.
In Star Trek Online, the empire is also a shadow of its former self following the loss of Romulus. By Delta Rising it has been reduced to a handful of colonies. On the other hand, the Romulan Republic is doing very well.
In David Weber's Hell's Gate series, the Ternathian Empire was previously a massive empire spreading across most of the planet of Sharona (essentially an Alternate Universe of Earth). Unlike most examples, the empire was not established out of a desire for expansion but instead to secure their borders against lawless brigands and organized raiders - and every time the new borders were stabilized, more cross-border raiders and brigands appeared, forcing the empire to expand to destroy them as well. Ternathia eventually withdrew from many of its outer territories when they became too expensive to maintain control of, turning them over to local governments in an orderly, controlled contraction of their borders.
Also from Weber, the Solarian League in the Honor Harrington series, a body comprising about 80% of the human interstellar population and which started as The Federation, is on the verge of becoming this, with graft, corruption and external pressure forcing it to the point of internal collapse.
Nabban from Memory Sorrow And Thorn is what happens when you go the next step beyond this- once a Rome-esque superpower, it had been in decline for some time and controlled only the core of its former territories, and then about a generation before the novels High King Prester John showed up and conquered it, making it only one province of his own empire. It's still the headquarters of the continent's dominant religion, though, and its greatest knight went on to become John's Number Two.
The Reynard Cycle: The Kingdom of Aquilia has shrunk down to one third of its size, and isn't even called the Kingdom of Aquilia any more due to the fact that the remaining third split into two warring halves long before the events of the first novel. One of the antagonist's primary motivations is a desire to reunite the Kingdom, and restore the Empire.
The Nansur Empire in the Second Apocalypse series, which has been steadily losing territory to Fanim jihads for centuries and retains only a shadow of its former glory.
Slaver's Bay from A Song of Ice and Fire consists of three allied city states that are the remnants of the Ghiscari Empire, which was conquered millenia ago by the Valyrian Freehold.
In The House Left Empty by Robert Reed, a series of EMP blasts and viruses crippled the worldwide communication grid and corrupting most databases, causing governments to effectively cease to exist, with millions of self-governed micronations popping up in their wake. The United States government still exists - the postal service is still around albeit very crippled, and people still pretend to pay taxes and file IRS reports.
In The Scar, agents from Armada visit a tiny island where a tiny handful of the Dying Race of anophelii — mosquito-people — are being kept isolated by the region's naval powers. Previously, the anophelii had reigned over the horrific Malarial Queendom, dominating and preying upon every race that had blood in their bodies.
The books of the Tortall Universe by Tamora Pierce have the old Thanic Empire, which turned into the sovereign nations of the Eastern Lands (Tortall, Galla, Tusaine, Tyra, and Maren).
Also by Tamora Pierce, the Pebbled Sea states of Circle of Magic arose from the old Kurchal Empire, which gave them a common language and a calendar. It may also have been a bit Roman, as one character references its coliseum fights.
In the Perry Rhodan series the Arkons are this at the beginning of the series. Several systems still pay lip service to their dominance but in reality they control only their own system. Then they are absorbed by the Terrans.
Many governments and their militaries in the Black Tide RisingZombie Apocalypse series, after the Hate Plague hits them, are almost totally destroyed, the surviving rulers controling only a relatively small part of their original territory.
In Vladimir Vasilyev's Treasure of the Kapitana, the Empire of Albion nominally controls much of its far-off lands. In practice, the local rulers pay lip service to the Empire, although they're a little more compliant if an Imperial frigate shows up in their port. One of the main characters is the youngest son of the current King of Albion, who is sent to the Euxine (Black) Sea to find the legendary treasury that was reportedly aboard the titular Turkish flagship sunk in a battle long ago. Supposedly, the treasure will replenish the Empire's coffers, allowing Albion to return to greatness. The King then sends his oldest son, the Crown Prince, with a fleet to find the true treasure - the secret to eternal life.
Live Action TV
The Centauri in Babylon 5, at least as the series is starting. The Shadow War causes them to briefly enter a new expansionistic phase.
Differently from most examples, they are arguably more powerful than in their heyday: the Expanded Universe shows they invented artificial gravity and antimatter-fueled reactors just in time for a civil war to force them to abandon most of what is now the League of Non-Aligned Worlds (with one of their former subjects developing the technology well beyond what the Centauri can do with it), and by the time the contraction stopped they had developed the ships, infrastructure and high-powered weapons to actually make use of that technology. The only thing that kept them from overwhelming the League of Non-Aligned World was a lack of will, and when the Shadow War caused the expansionist factions to come into power they first crushed the Narn (with some help from the Shadows, but it's shown the Centauri did a large part of the work), and then started twelve wars at the same time and were winning (albeit precariously, and again with crucial—and ultimately pricey—support from the Shadows) when Londo managed to force a stop.
In the Star Trek: Voyager episode "Dragon's Teeth", the crew awakens several hundred members of a species that used to rule the quadrant, who find that their enemies have overrun their old empire and that the name of their species is now a synonym for "foolish."
The Krenim Imperium in "Year of Hell", before Annorax started wiping out entire species with his giant spacefaring RetGone cannon in an attempt to restore the Imperium to its greatest glory. Unfortunately, he didn't take certain side-effects into account - wiping out their first race also wiped out a key antibody that had prevented a vicious plague from nearly wiping out the Krenim. His attempt to fix that cost him his home colony, and he spends the next two hundred years trying to restore that colony, while also nominally restoring the Imperium. It takes Janeway crashing Voyager into the time ship to hit the Reset Button, sending the Krenim back to vestigial status (and resetting Voyager so that the eponymous Year of Hell fighting the Krenim never happened).
The Imperium of Man has waxed and waned over the past ten thousand years, but is now unquestionably in a state of decline, so much so that scholars refer to the current era as the Time of Ending. Whole sectors are being lost to rebellion, alien depredations, or governmental negligence, and on every front the Imperium's enemies are closing in. The words most commonly used are "decaying" and "rotting," and fearful sages worry that it will be a Rising Empire such as the Tau that will ultimately inherit the galaxy. Which is not to say that Mankind plans on going down without a fight.
The Eldar don't have so much a Vestigal Empire as they do the bleached bones of one. Where they once ruled the entire galaxy unopposed and rearranged the cosmos at a whim, now they're reduced to a few spaceborne cities called Craftworlds, some primeval colonies on the galactic rim, and in the Dark Eldar's case a nightmare metropolis in the cancerous heart of a Portal Network. As such, they're frequently described as a Dying Race clinging to life as long as they can in other races' shadow.
The Necrons ruled the galaxy before the rise of the Eldar, and have emerged from stasis to find their domain overrun by primitive upstarts. Their technology, while arguably the most formidable in the setting, has not always weathered their 60 million year nap, they can't reproduce due to being Virtual Ghosts, and many of the lords who have woken up have developed eccentricities due to a mechanical version of Cryonics Failure.
Note that in all three cases, "vestigial" should not be taken to mean "weak". Even if their golden ages were millennia ago, these civilizations have held out for this long in one of the most ridiculously lethal settings ever imagined.
The Dwarfs' empire first got cracked when the Slann noticed that the mountains were no longer where they thought they should be, so they moved them back, without consulting the dwarfs who were living under them at the time. Since then they've been fighting a Hopeless War against an endless tide of orcish and goblin invaders, and they might have a chance at stabilizing if they weren't obsessed with settling old grudges, and the grudges arising from attempts to settle other grudges.
The ancient Elven empire was torn apart by civil war, splitting into the High Elves and Dark Elves, as well as the Wood Elves who stayed behind in their overseas colonies. The High Elves are slowly dying out, while the Dark and Wood Elves are stable, if prone to backstabbing or militant isolationism, respectively.
The Lizardmen's empire is down a few cities, and has lost contact with the most distant parts of their domain, but are doing better than some of their rivals in that they're actively rebuilding... just very slowly. Granted, several cities are still marked on their maps with Lizardmen equivalents for "Never Go Within Thirty Miles Of This Place Again", but it's a start.
The default setting in Dungeons & Dragons 4th edition, Points Of Light, is rife with these, most notably Human-controlled Nerath, Tiefling-controlled Bael Turath, and Dragonborn-controlled Arkhosia.
Unther in the Forgotten Realms. Up until the Time of Troubles it was a force to be reckoned with, ruled by Physical Gods. After the gods' mortal incarnations are killed, Unther becomes a shadow of its former self and is mostly annexed by its neighboring empire, Mulhorand. In 4E, Unther is one of multiple countries that was unceremoniously destroyed by the Spellplague.
Eberron has the goblinoid Dhakaani Empire, which was mostly destroyed 9000 years ago by an invasion from Xoriat, the plane of madness, then slowly declined. Well before that was the ancient Giant empire on Xen'drik, which was destroyed by the dragons. Survivors of both occasionally attempt to restore their civilization's former glory.
In Traveller, the Vilani Imperium. It was superficially powerful, controlling thousands of worlds when the Terrans found it. But it was senile, indecisive, and generally a meal waiting to be snatched by whomever discovered it. note Or, as its conquerors eventually found out, a dying elephant that would crush and suffocate anyone bold or unwary enough to try to topple it under its sheer dead weight. The Rule of Man inherited all the old empire's problems, and managed to prop it up for a while, but a thousand-year Dark Age came anyway.
Lookshy of Exalted fashions itself as the last remnant of the Shogunate, the worldwide Dragon Blooded government prior to the Great Contagion, reduced to a single (if securely independent) city-state.
The Realm itself is not quite there yet, but it is a lot less strong abroad for having spent the last five years drawing the lines in preparation for civil war, and being reduced to a fraction of its former power is a noted possibility. Some Dynasts would even prefer a Vestigial Empire; it would be easier to manage, and they don't have any greater ambitions than maintaining their own tremendous wealth and luxury.
The Lintha have been on a downward spiral since the fall of the Primordials. Depictions of the First Age show the Lintha Empire (which once ruled most of the West) to have been reduced to a small coastal state where pure blooded Lintha (the only ones able to use their magic and operate their technology) are virtually an endangered species. The default setting shows the vestigial remnant of that, where the Lintha are nothing but a few criminal families (with practices of incest and self-castration/mutilation) operating off of the back of a dying monster.
The Remanence of Myriad Song is ruled by the descendants of the Syndics' genetically engineered slave overseers and consider themselves the Myriad Syndicate, and just waiting for the Patrons to return. In the meantime, everyone else hates them.
The Principality of Belka from the Ace Combat series controlled a sizable chunk of the planet until it's economy collapsed and it started hemorrhaging territories until it was a quarter its original size. The plot of Ace Combat Zero: The Belkan War centres around its attempt to reclaim the states it permitted to secede, particularly the protagonist nation of Ustio. Speculations are abound that AC's Belka was the inspiration for the Nanoha's one, too.
San d'Oria from Final Fantasy XI was the game's original Vestigial Empire, wracked with internal strife but still fairly powerful. It now shares its former power among two other nations. Overshadowed by the Aht Urhgan empire, which fits this trope to a T. Political intrigue, encroaching hordes, you name it.
The empire of King Rhobar II in the Gothic series is going down the toilet in the first game, near collapse in the second game, and pretty much ceases to exist as a political entity in the third and the add-on, though most of the people and geography are intact.
The Empire of Tamriel is introduced as being on the decline politically, though not geographically (yet). The Province of Cyrodiil (the Capital) appears bloated and lazy, while various political factions are constantly vying for control of the outlying provinces. Two of the games (Daggerfall & Morrowind) deal with different Gambits by the Emperor to keep the empire together and delay its break up, while one game (Oblivion) has you actively saving the empire from an invading force and a conspiracy:
In Daggerfall, the hero is sent on a personal errant for the Emperor (the protagonist is "friend" with said emperor). The emperor's true goal is to have you find a Forgotten Super Weapon that was used to forge the empire and that you'll return it to him. You have the choice to give it to many factions, all with their own plot. Later games reveal that a Divine Intervention made all the game's endings happen at once, most of them cancelling out and bringing peace and some stability to the region.
Morrowind has the Emperor sending the player, who's a prisoner, to the eponymous province, so that he may join the emperor's Blades and fulfill a prophecy the locals have. Doing so would give the emperor a very religiously and politically powerful tool (you, the Nerevarine), as well as removing forces more hostile to the empire (Dagoth Ur & The Tribunal).
In Oblivion, the very heart of the Tamriel is attacked by The Legions of Hell and the emperor who has been the last link to keep it together is assassinated. Fortunately, he has an heir, but unfortunately he doesn't survive long. The leader of the Elder Council, High Chancellor Ocato, is appointed regent, but has his hands full keeping the Empire together. Argonia/Black Marsh secedes from the Empire a year after the Oblivion Crisis under the leadership of the xenophobic An-Xileel party, and Elsweyr soon follows, the latter becoming the loosely united Elsweyr Confederacy. Four years after this, the volcano at the heart of Vvardenfell, an island in central Morrowind, erupts, laying waste to the province. The Argonians, who had long been exploited by the Morrowind natives (Dunmer), invade and seize southern Morrowind. Five years after this, Ocato is assassinated, likely by the ultranationalist Thalmor group from the Summerset Isle province. The capital province of Cyrodiil falls into civil war as rival warlords struggle for the throne. After seven years, one warlord, Titus Mede, defeats the rest and is crowned emperor. The Empire begins to revive, but four years later the Thalmor seize control of Summerset Isle and secede as the independent state Alinor. Seven years after that, a Thalmor-led coup in the province of Valenwood causes the Empire to lose that province, which joins Alinor to form the Aldmeri Dominion.
Skyrim reveals that some time after the novels, things got worse. For a period of two years, the two moons of Nirn (the world the games take place in) disappear. When they reappear, the Aldmeri Dominion claims credit. Since the moons have significant religious importance for the Khajiiti natives of Elsweyr, the Elsweyr Confederacy divides into Anequina and Pelletine, Aldmeri vassal states. The Aldmeri Dominion then invades the Imperial provinces of Cyrodiil and Hammerfell seventy-one years later. After a long, brutal war that ends in a stalemate (at one point, a county, or "hold", of the province of Skyrim, the Reach, attempts to secede as the Forsworn Kingdom, but is quashed). Due to the peace terms, the Thalmor have a considerable presence in the Empire and given license to hunt down people who worship Talos, the Emperor Tiber Septim who became a god. Additionally, they receive southern Hammerfell. The Redguards of Hammerfell's refusal to accept this lead to the current emperor, Titus Mede II, expelling the province from the Empire. The Redguards, however, actually oust the Aldmer from Hammerfell. In the game itself, the player's choices can strengthen or weaken the Empire. The civil war (which is stoked by the Thalmor) can end either with the Empire re-establishing control over Skyrim, or Skyrim seceding from the Empire. Additionally, one can assassinate the emperor as part of the Dark Brotherhood, or choose to destroy the Brotherhood instead. Finally, the Forsworn king can either be rescued from his prison, or put down.
The Empire of Tamriel itself was built on the remains of the ancient Ayleid Empire after it was overthrown in a slave rebellion. The Province of Cyrodiil is loaded with ancient Ayleid ruins, and the Imperial Palace is a repurposed Ayleid fortress.
At least as late as Daggerfall (there is no canonical evidence afterwards), the Altmer clan Direnni ruled over the Isle of Balfiera (a much smaller island than Solstheim, let alone Vvardenfell). At their height (during the First Era) they ruled over a quarter of Tamriel as the Direnni Hegemony, but losses and overextension led to a gradual withdrawal and collapse. Given that this was over two millenia ago, the Dirennis don't really have any hang-ups about their former empire.
The Lilty Empire from Final Fantasy Crystal Chronicles once almost conquered the world, but eventually ran out of materials and shrank down to its Capital City. It seems to lack the political complexities, though their princess did run off after being cooped up in the castle...
The Tevinter Imperium. The player may not visit it in the games yet, but it's a big part of the world's lore and history, and its ruins litter the game. Their decline was brought about by a combination of a massive internal slave rebellion triggered by a immense barbarian invasion spearheaded by Andraste, who was a sort of fusion of Jesus and Joan of Arc who punted the Imperium right in the knockers and wrecked much of their power. Some centuries later, the Qunari showed up, settling in the northern islands, and started kicking everyone's collective asses across Thedas, including the Imperium's, until the combined forces of Thedas halted the Qunari invasions. The Imperium, rather than making an uneasy peace with the Qunari like the rest of Thedas, has been fighting a bloody and expensive and stalemated war with the Qunari ever since. In Dragon Age II, though, Fenris claims that Tevinter's power is slowly returning. Since Tevinter is an Evil Empire that relies on the worst of Blood Magic, this is a very bad thing.
The Orlesian Empire is also heading this way, with its capital having already devolved into a Deadly Decadent Court and its land being a fraction of what the original Empire possessed under Kordillius Drakon. With the outbreak of not one but two overlapping civil wars on its territory (as of Asunder), it remains to be seen whether Orlais will fare better than Tevinter did in Andraste's times.
The Empire in Parthenia in Dragon Quest IV is one of the more dramatic examples of this trope. Once a great nation, it is now only a single tiny village that contains a tent instead of a castle. The Emperor and his subjects are now happily making a living by growing medicinal herbs.
The Gittish Empire in Dragon Quest IX embodies this trope in a particularly creepy way. Centuries before the game starts, it seems like they at least dominated over one of the world's continents, before getting obliterated in a cataclysmic war. In the time of the game, an insane angel has brought back the Gittish Empire's king and army as undead monsters who have little if any awareness that they ever died. Now they just rule over a desolate and partially poisonous wasteland and a fortress full of slaves. You'd almost feel sorry for them if they weren't all such vicious bastards.
The Taiidan Empire was a full-blown one in the times of the first game, but by the beginning of the Cataclysm expansion it's reduced to the Taiidan Republic and a bunch of splinter bandit kingdoms, strong enough to launch an occasional raid against Hiigara, but by no mean a major player on the galactic arena anymore. Similar to the aforementioned Centauri, the kingdoms are mightily frustrated with such a state of affairs and seize a reckless opportunity by striking an unholy deal with a monstrous sentient virus designated as "the Beast". It doesn't work out for them.
In Homeworld 2, the Taiidani remnant makes up a part of the Vaygr armada, poised to finally destroy Hiigara.
The Hiigarans themselves can, possibly, be considered one, given that the old Hiigaran Empire was highly expansionist and was responsible for pissing off the Taiidani in the first place.
The Amarr Empire has seen better days. After the catastrophic collapse of the wormhole back to Earth, they were the first civilization to re-emerge from the Dark Age, re-discover space flight and conquer most of their neighbors. But after their catastrophic campaign against the mysterious Jove Empire, the Minmatar successfully seceded from the Empire, corruption became widespread, the Ammatar Mandate was revealed to be throughly infiltrated by the La Résistance and the Minmatar returned with a vengeance. However, Empress Sarum has managed to stop the decline, so they're not down for the count yet.
Meanwhile, the Jove Empire has been utterly crippled by a Despair Event Horizon-causing genetic disease, preventing them from taking any overt role in galaxy-wide politics.
Player alliances, such as Band Of Brothers, that were at one point in control of vast tracts of the map, but due to internal issues, wars, etc, were eventually crushed to nothing.
Both the ARM and the CORE in Total Annihilation start their campaigns from their home worlds, having lost their galaxy-spanning empires over the last four thousand years of non-stop war. All that's left are the armies squabbling over the ruins of a galaxy. (According to the intro and manual, that is. The core at least is implied to still have digital copies of many of it's civilians.) Notably, the expansion packs make it clear that after the war finally ended, the ARM managed to build itself up into a wonderful period of reconstruction.
In the Fallout series, TheEnclave consider themselves the sole and true heirs to the United States ofAmerica, despite only hanging on to Navarro and the Oil Rig in Fallout 2 (which they've lost), Raven Rock in Fallout 3 (which they've lost), and implied to have holdings in the Mid-West, specifically Chicago (which they'veNOT lost, yet). Once feared for their PowerArmor, airforce, and other pre-War technology, by Fallout: New Vegas only a handful of aging Enclave remnants live in the Mojave region, most of whom who are on the run and hiding from the New California Republic after the events of Fallout 2.
Caesar's Legion in Fallout: New Vegas is a young, aggressive militaristic empire with the weaponry, the manpower and the stones to take on the NCR. However they can become the Vestigial Empire if you assassinate Caesar and rally other factions like the Boomers, the Brotherhood of Steel and even the Enclave Remnants to aid the NCR in a key battle at Hoover Dam. Then if you defeat Caesar's most dangeous general, Lanius and win the battle, the Legion is effectively doomed to collapse. Even if you manage to talk Lanius into retreating, it's hinted that without Caesar, the general won't be able to hold the Legion together for much longer.
In Emperor Of The Fading Suns, a 4x space game where you take control of one of five noble houses in the attempt to reunite a dying galactic empire.
In antiquity, the troll empires controlled most of the world until the night elves drove them back. The Sundering and conflicts with humans, high elves, and their own people eventually reduced them to borderline barbarism. Attempts by Zul'jin and the Zandalari have been made to convert them into The Remnant.
The night elves dominated much of old Kalimdor until the War of the Ancients, and the subsequent Sundering.
Many of the human Seven Kingdoms. The Empire of Arathor played this trope straight, while the Kingdoms of Alterac and Lordaeron went a step or two further than this trope. The Kingdom of Azeroth (later renamed Stormwind) played it straight in Orcs & Humans, only to invert it in the period between Tides of Darkness and Reign of Chaos, when it was rebuilt.
The nerubians who are not part of the Scourge are about as vestigial as you can get: Kilix the Unraveler and his two guards are the only non-undead nerubians present in World of Warcraft. He speaks of rebuilding the old Nerubian empire (with the Player Characters helpfully clearing out key Scourged Nerubian strongholds), meaning he either speaks for a significant number of well-hidden Nerubian refugees who never appear in the game, or is simply deluded about his prospects.
According to the Encyclopedia Exposita, the Batarian Hegemony fits this trope perfectly. Balak even laments it in the Bring Down the Sky DLC, when he embarks on a passionate, long-winded rant to Commander Shepard. Balak blames Humanity and the Systems Alliance for the abysmal state of his people and uses his arguments as justification for slamming the asteroid X57 into a planet colonized by humans under Alliance control.
It's even worse off in the third game. The Reapers began their invasion of the galaxy in Hegemony space, and the batarians got smashed so hard they didn't even know what hit them. They'd been secretly studying a derelict Reaper that had been captured decades earlier, all to gain a technological edge to fight the human Systems Alliance. In the process, all of their best scientists and most of the leadership were indoctrinated and opened the door wide open to the Reapers. If he was spared in the above DLC, by the time Shepard meets up with Balak again, he is actually the highest ranking batarian military official left.
The Reapers in Mass Effect 3 threatened to turn a lot of the galaxy's civilizations into one. Ironically, the Protheans' chosen successors, the asari, most closely fit the bill after the fall of their homeworld Thessia.
Almost enforced in Medieval II Total War. The Byzantine Empire is a playable faction that starts off with a very well-developed capital and a powerful army list... but a capital sandwiched between the rising powers of Hungary, Venice, Novgorod, and the Ottomans, and an army that cannot keep pace with the other factions' advances in the endgame. It's possible to avert the Fall of Constantinople, but doing so is usually a race against the clock.
Historically-minded game mods like Stainless Steel take this even further. In a Late Start (1220 AD) campaign, the Byzantines' holdings are scattered across western Greece and Anatolia, while their capital and Greek heartland are held by Crusader forces. Then there's the 1450 AD scenario seen in I Am Skantarios, in which the Byzantines have Constantinople, a fortress at Corinth, and a horde of Turks knocking at the door.
Ravenmark: Mercenaries starts with the once-great Empire of Estellion barely holding its own against its former ally the Commonwealth of Esotre and the newly-arisen Varishah Federation. The territory making up the Federation are made up of provinces rebelling from the Empire. The Twin Cities, the cultural and economic core of Estellion, have seceded and resist any attempts to take them.
The Azracs of Age of Wonders have by the sequel's expansion been reduced to a nomadic people controlling naught but a barren desert. Worse yet, by the beginning of the campaign that introduces them they're being shaken by a civil war.
By the beginning of the sequel, humanity could be counted as this as well as they have been weakened by dragons they once hunted and brought under the control of the wizard Yaka (Who had previously ruled the Azracs) and his Tigran followers. All this changes by the expansion, when they're once again a dominant power.
If you're not too careful, this can happen in just about any RTS or turn-based strategy game, from Total War to Civilization. A few military losses can drain the treasury, the loss of a city or two can set back income and production, until finally the enemy is at the gates of your capital.
In the first Imperium Galactica game, the Player Character is tasked with restoring the once-great Galactic Empire. In the game, you have to fight off several powerful alien races as well as many splinter human factions. Older Is Better is also invoked once you reach the rank of Admiral. You are given the last of the Leviathan-class flagships (you can't build more of them) built during the heyday of the Empire, which outclasses any other flagship.
If the sequel is believed to take place in the same continuity, then the Empire is long gone by that point, having been replaced by the SolarianFederation. One of the subplots is a mad Emperor who had himself put into cryosleep to wait for the time when he is needed again. The Shinari Republic is trying to find and revive him to plunge the galaxy into a War for Fun and Profit. Oh, and many of the minor races in the game are actually Lost Colonies of genetically-modified humans, which also fits the trope to an extent.
In The Gamers Alliance, the Yamato Empire becomes a mere shadow of its former self after the demons conquer it and enslave its populace in the aftermath of the Cataclysm. Four demon duchies now rule the lands of the former empire, but some Yamatian rebels still fight a guerrilla war against their new demon overlords in hopes of driving them away and restoring their homeland to its former glory.
Word Of God says that the Empire of Smilodons in the Basalt City Chronicles once ruled western coasts of both Americas, and even the North-Eastern coast of Asia, but is now relegated to a few islands off Alaska.
Subverted in Decades of Darkness. The Restored Empire, a loose union of former British colonies led by Australia after the fall of Britain itself, appears to advertise its empire-in-exile status in the title, but is actually the free-est, most vibrant, and nicest place in the southern hemisphere and possibly the world as of the timeline's end. At least for English-speaking people.
Yaman in Open Blue is suffering from decades of decadence and corruption, and can only prioritize maintaining its outward appearance. Avelia, one of the two dominant empires of The Verse, is slowly following in Yaman's footsteps.
Several in the Chaos Timeline, most notably the remaining British royal family. They flee to New Albion (New Zealand) after Britain turns republican and eventually socialist. A civil war over throne succession issues eventually rocks the country in the 1960s and effectively splits it in two, the South Island standing behind the resident Cloud Cuckoo Lander and the North Island standing behind a certain Elizabeth. Talk about the British royal family being the Butt Monkey of this timeline.
Orion's Arm: The Terran Confederacy is as similar to the Terran Federation as the Holy Roman Empire was to the Roman Empire.
Taken to the extreme in Hitler Rants, in which Nazi Germany consists entirely of a single bunker located in Berlin, not helped by the fact that members of Hitler's staff actively plot antics against him, not to mention the entire navy (which also consists of two U-Boat crews and one drunken Captain, all of whom also support antics). This also seems to be more or less the case for Gaddafi, though it is averted by Stalin and the Soviet Union, which is still extremely powerful.
The United States of America that (re-)coalesces after the collapse of the Scottist regime has lost almost half its territory. However, it remains an international presence, and in the 1930s launches a bid to regain what it has lost.
Spain in 1900 was a world power with perhaps the greatest colonial empire on Earth. A large portion of it was lost in the Great War, then the disastrous civil war following it, and after losing a war with newly unified Germany in the 1920s, even parts of mainland Spain (the Basque Country, Catalunya, Galicia) gain independence.
Kongo. The country itself (the former Scandinavian colonies in Africa) is where the Scandinavian Emperor fled to after the Proletarists took power back home, making it a vestigial empire of Scandinavia. Then, in the 1920s, first Abyssinia, then the entire rest of East Africa broke away in a somewhat messy collapse, leaving Kongo as the Vestigial Empire of a Vestigial Empire.
Avatar The Last Airbender shows us Chin Village. Three-hundred years before the series, the Earth Kingdom (except for the capitol Ba Sing Se) was grabbed under the boot heel of Chin the Conqueror. When he died, his empire imploded, leaving only the teeny-tiny Chin Village.
"We used to be a great society! And now look at us!"
Examples in this section are listed in (mostly) chronological order:
The First Intermediate Period (2181-2055 BCE) counts as a highly restricted example. After the collapse of the Old Kingdom, the regional lords—previously the Pharaoh's governors—took complete control of the country, but for the first part of it (the Seventh and Eighth Dynasties) there was still a Pharaoh at Memphis. However, his power was completely nominal; at best, he might have had a religious role outside his relatively small domain around the once-great capital. (Records of the period are very sketchy, seeing as it was frickin' four thousand years ago.) Eventually, the Memphite pharaohs collapsed, and the lords of Heraclitopolis in Lower Egypt (the Nile Delta in the north) and Thebes in Upper Egypt proclaimed themselves Pharaohs and fought for quite some time before the Theban Eleventh Dynasty conquered Lower Egypt and established the Middle Kingdom.
Egypt during the Twentieth Dynasty and 3rd Intermediate Period. The country was united for most of this time, but it lost control of its empire in the Levant to various independent kingdoms (Israel being the most famous), its western territories to local raiders and Greek and Phoenician settlers, and Nubia to the Nubians, who would occasionally conquer Egypt itself for good measure. When it wasn't being ruled by Nubians—and particularly in the Twentieth Dynasty—however, Egypt was very much an ex-empire in splendid isolation, cut off from the affairs of the outside world.
The Eastern Zhou Dynasty ended up like this. After the capital was moved, the central government gradually collapsed, as regional lords began to assert their independence from the Zhou monarch and his officials. This decay started at the edges, but within two hundred years, the king had lost all his authority outside his relatively small personal domain.
The entire history of China has been zigzagging this, alternating between world-spanning empires and domestic collapses. See below for more details.
Iran's history is interesting. Achaemenid Persia was once a world-spanning empire, encompassing most of the civilized world and featured in the annals of most others. Alexander knocked it out while they were still at their peak. After a while under the Seleucid Greeks, the Parthians established an Iranian empire that while it was constantly at pains to maintain its western border against the Greeks and later the Romans, managed to establish a firm hold on Central Asia and the Persian Gulf that the Achaemenids never managed; this is even truer of the Sassanids, who very nearly rebuilt the empire as it was in the time of Darius under Khosrau II, when the tide of the war turned in favor of Byzantium...just as the Muslim Arabs knocked the whole empire out in one fell swoop. After that, Persia would spend a lot of time being either a province of someone else's empire (the Caliphate, the Mongols, and an ever-rotating cast of Turks) or divided among squabbling warlords (often Turks); there would be one more great Persian empire (the Safavids), with subsequent dynasties leaving something distinctly to be desired.
Alexander the Great's empire stretched from Greece and the Balkans to modern day Iran and Afghanistan. It started with him and barely outlived him, but it left behind quite a few successor states in Egypt, Persia, Greece and as far as India. Although influenced by the native cultures they ruled over, these kingdoms retained a strong Greek culture and a reverence for Alexander and his dynasty.
Many of the aforementioned kingdoms became this themselves, notably the Ptolemaic empire (who went from ruling practically half of the Eastern Mediterranean to barely maintaining a hold on Egypt) and especially the Seleucids (who ended their dynasty as the ruler of a handful of cities in Syria).
The Western Roman Empire and its ever-decreasing territory during the 5th century is a rather good example. By 395, its last partition with the Eastern Roman Empire, the West included Britannia (Wales, England), Gallia (Gaul: France and certain areas of the Low Countries), Hispania (Spain, Portugal), Italia (Italy), Dalmatia (Croatia), Mauretania Tingitana (Morocco), Mauritania Caesariensis (western Algeria), and Africa province (eastern Algeria, Tunisia, Libya). Imperial troops left Britannia between 407 and 410, leaving the Romano-British to fend for themselves against invasions. Gallia and Hispania were increasingly settled by Germanic populations from c. 412 onwards. While often allied or even subordinate to the Romans, they set up regional kingdoms and eventually become fully independent. The last Roman governor in Gaul, Syagrius, fell to the Franks in 487. Most of the North African areas fell to the Vandals between 429 and 439. The Vandals use their new ports to replace the Romans as the chief naval power of the Mediterranean Sea. Italia fell to its own Germanic mercenaries in 476. Dalmatia followed it in 480. By the end of the century what was left of Roman rule in the west was an independent but isolated Mauretania Tingitana. Eventually Belisarius took it back for the East, but then the Arabs came along...
The so-called Byzantine Empire, the Roman Empire's eastern half, centred around Constantinople/Byzantion, lingered for just under a thousand years after the better known fall of the western half. It spent most of that time gradually losing territory, power and influence, though it also had several resurgences — one under Justinian and Belisarius, one under the Macedonian dynasty, and one under the Komnenoi emperors. It spent the last century or so of its existence as a few disconnected regions and cities around the southern Balkans, until the Ottoman Turks put it out of its misery in 1453; technically, though most forget it, the last vestige of Roman power was not Byzantium, but the small Empire of Trebizond, which did not fall until 1461. This example is probably closer to fictional portrayals than most others on this list, in that for a long time Constantinople's wealth and glory lingered, even if they could never recover the political or military power of the old empire. In fact Basil the Bulgar Slayer is believed by some estimates to have been worth almost 170 BILLION in modern US dollars, placing him among the top ten richest men to have ever lived. That last century or two, however, it was simply a shadow of its former self, barely holding on.
The Byzantine Empire was the Vestigial Empire of The Roman Empire making this perhaps the most spectacular example in history. And then the Vestigial Empire retreated to [ANOTHER Vestigial Empire in the form of the Empire of Nicaea (1204-1261), which was formed by refugees of the Imperial court and aristocracy after Crusaders occupied Constantinople. It managed to reconquer its old capital after more than half a century. The restored empire then had yet another vestigial empire in Trebizond, above.
Bear in mind that it's hard to call Byzantine decline terminal before the later Komnenoi, since all empires fluctuate in power to some extent, especially on their frontiers.
Brunei once had an empire throughout most of the Borneo Island and other islands, like parts of the Phillipines, as well. It is now a small enclave of Malaysia in Borneo. Made more jarring because Borneo is named as such because of Brunei. The nation's substantial oil wealth helps cushion the blow, though.
The 12th century Fatimids and post-11th century Abbasids are also good examples of this trope. The former went from a vast empire that spanned from northern Morocco to Syria to a rump state that was restricted to Egypt in about a century, while the latter went from dominating most of the Muslim world during the late 9th century to a remnant that had no real power outside central and southern Mesopotamia in about two centuries.
The Caliphates in general. The Rashidun Caliphate expanded from the city of Mecca to swallow up all of Arabia, North Africa, the Middle-East and Persia, before it was internally dismantled by the Umayyads. The Umayyad Caliphate was one of the largest contiguous empires in history, spanning from Persia to Spain. It was then overthrown by the aforementioned Abbasid dynasty, and the Umayyad dynasty fled to Spain and established a new Caliphate at Cordoba, which later disintegrated into warring factions which were all annexed by Portugal and the Spanish kingdoms following the Reconquista.
The Mongol Empire. It used to be one of the largest empires ever, conquering many well developed societies under it, till it stretched all across Asia, from the Caspian to China. Now, its back at former position as a swath of desert, and a bunch of nomads. It has the lowest population density (people per square mile) in the world. And it was the largest empire ever up till its time by far, and no empire since—save one—has ever matched it.
This is also one of the quickest examples of this trope happening. Very soon after Genghis Khan died, his empire split into several Khanates, which took a while to collapse themselves.
The Iroquois Confederacy, or Haudenosaunee (The Longhouse Builders), a league of nations formed somewhere between 1450 and 1600. A few historians even argue for dates as early as 1142 based on astronomical details in oral tradition. Aside from being a highly sophisticated democratic republic - they had merit-based offices, bicameral legislature, and a constitution (unwritten, of course, having no writing system). They were formidable military opponents, and were busy conquering and annexing their way through half the continent when white people showed up in North America. To make a very long story short, European influence caused massive cultural, political, and spiritual changes—to say nothing of the various introduced Old World diseases that cut the Confederacy's population by at least 50% and possibly by as much as 90%. These, combined with a few military disasters (like backing the Crown during the Revolutionary War), caused the Confederacy to become severely damaged and fragmented. Now all they own are a handful of reservations, and probably a good 90 percent of Americans haven't even heard of it. However, it's still around, it's still a nation, and it is still the world's oldest living participatory democracy.
The Sengoku Jidai came about due to the decline of the Ashikaga Shogunate. In this case, the decline of the Shogunate's power was not a result of Japan as a whole weakening, but of the growth of trade and wealth in the peripheral regions of Japan, and the resulting growth of power in the hands of local daimyo at the expense of the central administration. Eventually, things boiled over to the point where the capital at Kyoto itself became a battleground for warring daimyo, and this kicked off over a century of strife before Oda Nobunaga put the Ashikaga out of their misery. It took a few more decades of war before Toyotomi Hideyoshi put Japan back together, though he could not prevent his death from causing a Succession Crisis.
The Mughal Empire, before the British East India Company put it out of its misery in the early 19th century. The Mughals are the most recent example, but India is scattered with ruins of long-dead empires, like the Gupta Empire, the Vijayanagara Empire, and the Maratha Empire.
To detail on the (chronologically) last part: the Mughal Empire started out as the remnant of an empire rising up from the ashes of the Mongol Empire (thus being the vestigial empire of a vestigial empire), until they overran the Delhi Sultanate and replaced it. From there, they expanded and took over most of India, taking advantage of the Vijayanagara Empire, its only possible rival, entering the state of Vestigial Empire after a fluke defeat against the Deccan Sultanates, until the rise of the Maratha Empire made their authority nominal. From then on, Mughal authority was mostly nominal, with the real power residing in the hereditary governors of the Mughal territories, formally vassal kings and the various East India companies of the European nations (among which the British one was the one who ended up triumphing), with the Maratha themselves becoming a Vestigial Empire and a confederation formed by five mostly independent kingdoms (that would end up being absorbed by the Madras Presidency of the British East India Company), until emperor Bahadur Shah II, partly hoping to restore actual Mughal power, supported the Mutiny of 1857 (started as a mutiny in the Bengal Army of the Company's army due the Company supporting religious and secular offences to the local culture and land grabbings and ignoring the European officers' and noncoms warnings that the troops were getting enraged, and then becoming a full-blown war against multiple Indian states) and was proclaimed Emperor of India. When the British won, the second thing the Raj that replaced the Company rule did was to depose him (the first being eliminating the causes of the rebellion), with Queen Victoria being proclaimed Empress of India a few years later.
19th and 20th century Spain fits this trope to a tee: losing its empire and all pretensions of world power status, sinking into a deep economic decline, dominated by an over-powerful nobility, racked by constant political instability, coups, and the occasional civil war. Attempts to lord over its former South American colonies led Spain to get its ass kicked by them in the Chincha Islands War. Lingering imperial delusions and hubris were finally shattered in 1898, when they were quickly and brutally defeated by the United States (mind you, the American armed forces were viewed as a joke in 1898, making this especially humiliating), but not much changed after that.
Spain annexed Spanish Morocco (mostly present-day Western Sahara and coastal territory around Tangier) in 1912, hoping to recover their international prestige. Instead they almost immediately fell afoul of hostile Riffian tribes. From 1921 to 1926 they fought a bloody guerilla conflict with Abd el-Krim's forces, winning only after France intervened. This sliver of mountainous desert remained Spain's marginal claim to world power status until 1956.
Portugal, similarly. Lampshaded, albeit symbolically, in its national anthem. Translated: "Heroes of the sea, noble people, valiant, immortal nation, raise, today, once again, Portugal's splendor!".
For some 20 years after they fled in fear of Napoleon, the seat of the Portuguese monarchy and capital of the Empire was Rio de Janeiro, Brazil, making Brazil a "united kingdom" (of Brazil, Portugal and the Algarves) and also making Brazil the only former colony to ever become the capital of the empire it belonged to. Later on, Brazil was one of the few colonies to gain independence peacefully. (And by "peacefully" we mean "after about two years of irregular warfare with only a few dozen thousand battle deaths." That this was actually considered peaceful says something about the wars of independence in the surrounding Spanish colonies). This was why Brazil was an empire in its first half-century of independence, and probably would still be had it not been for some rich aristocrats declaring staging a coup and declaring a republic to protect their rights against the leveling Imperial family (Princess Isabel, daughter of D. Peter II, signed the Lex Aurea in 1888, outlawing slavery).
The Ottoman Empire was so far gone by the 19th century that Russian Czar Nicholas I coined the term "sick man of Europe" to describe it, and further noted that it was "falling to pieces." Subverted when the Turks wised up and became strong again during the mid-19th and again early the 20th century...only to chose the losing side in World War One and now Turkey only has Anatolia and Eastern Thrace left. At least they still have Constantinople, now named Istanbul. And now there's been an insurgency by the Kurdistan Workers Party and various other assorted groups going on since the 70s. Many of these seek to create an independent country in the southeast for the oppressed Kurdish minority. Armenians are also sore over losing much of their homeland after the Soviets conquered Armenia and gave Turkey over 85% of their land, but their having any of it returned to them is rather unlikely unless Turkey is finally forced to pay them genocide reparations.
The Carolingian Empire once occupied a HUGE chunk of Europe, from Spain to Germany and a large chunk of Italy and other nations as well. It is now represented by Andorra, a delightful little enclave between France and Spain, and the 191st country in the world by area. Andorra is the only remaining daughter of the Carolingian Empire, as said in its anthem. Or "her" anthem, as it would seem.
The Principality of Liechtenstein may not seem much today, but it is arguably the last remaining piece of the old Holy Roman Empire. It probably helped that the ruling family possessed considerable land and clout to retain their power even after Napoleon signed its death warrant. And surprisingly enough, prior to World War I the Principality was somewhat larger, having included properties scattered across Austria-Hungary.
Andorra identifies itself with the Holy Roman Empire as well.
Austria under the Habsburgs once held hegemony over pretty much all of Central and Eastern Europe, especially during the 16th-17th Century. But by 1914, the Dual Monarchy had long become (perhaps not fully justifiably) the basis of Ruritania for much of Europe. The next decades would see the country dismembered, absorbed into Germany, and ultimately reduced to only a fraction of its former territory. Indeed, given their shared history, much of that could be said of Hungary as well; a quick look at the complete lyrics of the latter's national anthem ought to give it away.
If you look closely as the Hungarian anthem, the Himnusz, it's actually a surprisingly solemn hymn lamenting their lost achievements and calling on God Himself to pity their fallen glory.
The Habsburg Monarchy also tended to see itself as one to the Holy Roman Empire.
Where once Britain ruled a quarter of the world, she now maintains Gibraltar, The Falkland Islands, some delightful rocks in the Caribbean and the Indian Ocean, some rather more windswept rocks in the Atlantic, and the headquarters of the Commonwealth, which is about as loose an organisation as it gets. One wonders if JMS had it in mind when writing Londo's dialogue quoted on this page. One notable legacy of the British Empire that is near-inescapable is English, the international lingua franca of business, science, technology and aviation. The UK, however, downplays this to the extent that, despite its dramatic territory loss, it still wields a disproportionate amount of influence and power. The UK retains its permanent seat in the UN Security Council, meaning it could theoretically (although this is highly unlikely) veto motions issued by such powers as the USA and the PRC. Through its membership of the Security Council, its position as current head of the Commonwealth and its various other ties with former colonies, British influence extends to a majority of the Anglosphere. The defeat of Argentina in The Falklands War, accurately dubbed as "The Empire Strikes Back", went a long way to show that the UK had not lost its status as a major power. This is probably best shown in the high Euroscepticism and general mild jingoism in Britain - we have lost our Empire, but have not quite realized it yet. Inner London is a monument to this - all manner of grand Victorian palaces and state buildings for an impoverished northern welfare state.
Britain is also a key member of NATO, is an acknowledged nuclear weapons state, and still has the world's sixth-highest military budget, is the world's seventh-largest arms exporter (thank you BAE Systems!), and is the world's sixth-largest economy (by GDP, nominal) (thank you City of London!). She is also one of only three countries able to project power effectively anywhere (the others being fellow Vestigial Empire France and, of course, the United States), thanks to it's still powerful Royal Navy.
The French also downplays this to a degree like the British do, and many of the same traits apply to it (NATO member, nuclear weapons capability, fourth-largest military and fifth-largest economy. They remain a powerful force in the world and in Europe and Western Africa in particular, both by themselves and through their influence with the EU. That, and they still have a number of larger overseas territories around. Not bad for a bunch of Cheese-Eating Surrender Monkeys.
Unlike what is commonly believed, the expression "lingua franca" is not however a vestige of France's former power and influence. It actually means "language of the Franks" (not the French), and arose as a result of the medieval Arabic use of "Franks" to denote any and all Western Europeans (or the Western Christians/Catholics, since at the time there wasn't any distinction between the two).note Eastern Christians were another story; Muslim Arabs were quite familiar with them, seeing as they tended to literally live next door, as Christian Arabs. Not at all surprising considering the Franks and the subsequent empire they founded under Charlemagne essentially re-established political order in a Europe that hadn't seen any since the fall of the Roman Empire, and one that would later evolve into the Holy Roman Empire. The original Renaissance-era lingua franca (Mediterranenan Lingua Franca) consisted largely of Italian, with a vocabulary that also incorporated many words and phrases from Turkish, French, Spanish, Greek, and Arabic. Many different languages both before and after have also been lingua francas, of course.
Germany, as with Britain and France, also downplays this. The German Empire until World War I was small and compact, but was highly organized and had one of the best-trained armies in Europe. After the war, Germany was forced to give up its African territories and much of the land it had won from Russia, giving the rest to Poland. With the start of World War II, Germany captured Poland, Belgium, Holland, Denmark, Luxembourg, Norway, Northern France, and much of the Western USSR in just two years, before being defeated and many of its cities leveled. Today, Germany has a fraction of the territory it held at its height, but is highly influential within the European Union, and though it's not a permanent member of the UN Security Council, it remains an economic powerhouse in Europe.
Sweden was once a great power and its armies were a terror of Central and Eastern Europe. Now, it is a small country in the corner of Europe best known for Abba, depressingfiction, Ikea, and (admittedly) a few cool planes.
The European Union itself is a quasi-federation of many vestigial empires cited here: in fact, having the world's biggest GDP, the first millitary in terms of troops and the second biggest military expenditures, the world's second reserve currency, the world's third largest population a very respectable amount of soft power, and the fact that it one of the few polities to have known a significant expansion in the post WWII, the UE could very well be the first alliance of surviving Vestigial Empires turning into an Hegemonic Empire... That is, if it had a strong central government which it still lacks.
In the early twentieth-century, Imperial Japan was the dominant great power of the Pacific thanks to its rapid industrialization in the late nineteenth-century, holding its original islands, Korea, parts of Manchuria, and many islands in the Pacific (including Taiwan). It shocked the "civilised" Western nations by curb-stomping Russia in 1904-5, and had plans to expand into China and Oceania during The Great Depression. Before it took pretty much all of East Asia during World War 2 before being defeated, they also had significant influence in the area due to their powerful navy, leading interventions into China and Siberia, and annexing all of Manchuria before World War 2. Now, thanks to their defeat during World War II and their subsequent occupation by the United States, Japan consists almost entirely of just its original islands, and its military has been constitutionally neutered.
Again, downplayed as well, considering that they re-emerged as an economic powerhouse - rivalling that of Germany (or depending on how you see it, and when it was, even the US) - and a major exporter of popular technolgies, particularly cars and consumer electronics (hence the catchphrase "Made in Japan", particularly in The Seventies and The Eighties), and until now the largest car company in the world is Japan based. For a good deal of 1950-2000, it was the one of the very few First World countries that wasn't predomiantly Caucasian. While that is fading (first thanks to South Korea and Taiwan, then China), Japan is still the third biggest economy in terms of GDP, and its currency is still considered to be a major player in markets - investors relied on the the relatively stable yen during the 2008 GFC when the dollar and euro became unreliable. Also note that Japan can be considered to be a potential nuclear state - so far the only known reasons it isn't actually so is due to the constitution, public opinion, and holding nukes seen as redundant due to the Japan-US alliance.
The Qing Empire was a shadow of its former self by the time of European (and later, Japanese) expansion into its territory, and modern China is noticeably smaller than it used to be. Mongolia is now independent, and Taiwan its own country to say the least (the details behind that are rather complicated and will be discussed below). In spite of going through a humiliating cultural and economic decline in the past two centuries, most of its key territories were intact and the country was still by far one of the largest and most (over) populated countries in the world. With the resurgence of Chinese economic and political power in the 21st century, it can be said that this trope applies to China no longer.
It should also be noted that at various points of Chinese history, the empire has gained territory, lost territory, regained territory, or even split up and later reunited. Both the Warring States and Three Kingdoms periods follow after the fall of a major dynasty (the ancient Zhou and imperial Han respectively) and involved disparate successor states vying among each other for influence. They were succeeded by the Qin Dynasty (recognized as the first actual "Chinese" empire) and the Jin Dynasty respectively.
And on top of that, apart from the Yuan dynasty which was part of the Mongolian Empire, the Qing dynasty had the largest territory in the history of China. Even with the loss noted above, the current Chinese territory is still larger than most of the territories in other dynasties.
Now that we come to Taiwan, the actual title as a country is the Republic of China, as opposed to the People's Republic of China that serves as the title for the mainland proper. Formerly a part of China itself, the territory developed its own distinct nationality when it became the refuge of the Chinese Nationalist government in 1949. For awhile, it continued to represent China and even retained its UN seat until 1971, when it was given to the PRC. As time went on and the government became more native, the claim to being the sole representative of China was de-emphasized to the point where it no longer exists in fact (theory is another question; see below). While relations with the mainland have thawed over the years, it is still uncertain at this point in time what Taiwan actually is: the remnant territory of the former Chinese government or an independent country in its own right? However it goes about it, declaring for one or the other has repercussions that would adversely affect the territory and its international relationships.
As we mentioned before, the government ruling Taiwan still calls itself the Republic of China and still theoretically claims all of the PRC, plus Mongolia, half of Tajikistan, and parts of Russia, Bangladesh, Bhutan, Burma, and Pakistan. Why? Well, besides nationalist pride, there's a very simple reason for doing so: Declaring the actual de facto situation to be reality is very likely to piss off the PRC. Why? Because the PRC's claim that Taiwan is a province of a single, united China meshes very neatly with the ROC's claim that Taiwan is a province of a single, united China...the only difference is which single, united China it is a province of. The current situation allows both sides to claim the current situation as an extended cease-fire in a civil war in a single country, which suits both sides' propaganda. A declaration of a Republic of Taiwan with no claims on the mainland would run counter to the PRC's claim that Taiwan is a rebel province, and would therefore require a response, probably an armed one... Confused? You should be.
The situation between the PRC and ROC can be summed up as follows. They both agree that there is only one China. They just disagree on who the leader of China is.
The Polish-Lithuanian Commonwealth. At one point it was a Central European superpower, spanning from the Baltic Sea on the north to the Black Sea in the south. The Commonwealth managed to successfully invade what would later become the inpenetrable Russian Empire. Twice. They managed to survive near-total Swedish invasion, while defending themselves from Hungary, the Cossacks and other neighbours at the same time. They also saved Austria, and by extension, the rest of Europe, in 1683. Internal bickering, noble houses and confederations selling out to neighbouring superpowers, and general anarchy - all this led to the Commonwealth's three-stage partitions at the end of 18th century. Although Poland managed to rebuild some of its holdings after WWI, its current, post-WWII size is very, very unimpressive. Still, Poland's current borders are quite close to the way they used to be, pre-Commonwealth.
Size-wise it's not unimpressive at all, the Poland still grew bigger, just in the western direction. The post-WWI "rebuilt Polish holdings" were actually Western Ukraine and Western Belarus, with the terroristic La Résistance added for free! Even after Molotov-Ribbentrop pact USSR still didn't hold Western Galicia (with Peremyshl', or, in Polish, Przemyśl) and Białystok. And yet, the Poles are quick to blame the Soviets for capturing "their" territories, while preferring to forget that their new post-WWII territories were mercilessly taken from Germany by Stalin and then given to the "friendly people of Poland" by the same Stalin, with all the Germans deportated so that a new La Résistance wouldn't rise in Poland. In the end, Poland got these new, German-free lands, for a price of losing their chance to play theEmpire at the expense of Ukrainians and Belarusians.
The country's anthem speaks volumes of this trope, the lyrics beginning with the phrase "Poland is not yet lost..."
The Dutch Empire once consisted of the following: South Africa, Formosa (Currently Taiwan), Suriname, Sri Lanka and Indonesia (not including their various coastal settlements in Africa, America and Asia). The remnants of this empire are a few islands in the Caribbean and a large influences in all kinds of languages, ranging from Afrikaans, English and even Japanese.
The Dutch Province of Friesland used to be an kingdom stretching from Belgium to Denmark and Cologne. Since the middle ages its power declined and now it's one of the least populated provinces.
The Kievan Rus' (the original East Slavic state) used to occupy what is now Northern Ukraine, Belarus, and parts of Russia. It was a powerful state on par with the Western kingdoms whose royalty intermarried with the West. Then the Mongols came, completely devastating the princedom. In the following centuries, the nation would never again regain the former glory, although there were several attempts, such as Galicia-Volhynia, Svitrigailo's faction in the Grand Duchy of Lithuania, and the Ruthenian Cossack state (eventually annexed by the Russian Empire under Catherine the Great). Ukraine considers itself to be an heir to the Kievan Rus', especially since the Ukrainian capital of Kyiv was originally the capital of the princedom. Interestingly, the current territory of Ukraine (the second-largest nation in Europe after Russia) is not that much smaller than that of the Kievan Rus' at the height of its power (however, only central and western Ukraine correspond to old Ruthenian core territories, while southern and eastern Ukraine was colonized much later). Military and economic power is a different story, though. It's telling that the anthem of Ukraine starts with the words "Ukraine's [glory and freedom] are not dead yet".
Incidentally, the Grand Princes of Moscow (and later, the Tsars of Russia) were descended from a collateral line of the Kievan Rus', and they claimed to be the rightful heirs of the Roman Empire after the fall of Constantinople to the Turks by virtue of the fact that one of their rulers married a Byzantine princess. If you've been reading this list closely, you might have noticed a common theme by now.
Yugoslavia was originally an idea by Serb nationalists to create a Serbian empire out of the dying embers of the Ottoman and Austro-Hungarian empires. After World War I, this was going well - Serbia was given most of the Balkan territories of the two now defunct aforementioned empires, and the Kingdom of Serbs, Croats and Slovenes was formed. Then came World War II and an Axis invasion in 1941. Two resistance movements emerged - a Serbian nationalist movement known as the Chetniks, and a left-wing front known as the Partisans led by Josip Broz Tito. The Partisans won, and retained Yugoslavia as a socialist republic, but Serbia, now rather than being dominant, was one of six equal constituent republics in a federation. After Tito's death, Yugoslavia crumbled until by the late 1990s, only Serbia and Montenegro remained, continuing to call their state 'Yugoslavia' until 2003. In 2006 Montenegro seceded, and while it remains legally disputed, Kosovo has been de facto independent since 2008.
Russia had fallen into this in the The Nineties. Under the Soviet Union, Russian influence extended from the Pacific Ocean to the Danube to the Caribbean. They were the first to send a satellite, and then the first humans, into space. In the first post-Soviet decade, its military was engaged in bloody, indecisive war in Chechnya, had to abandon its only space sation and struggled to maintain influence over the other former Soviet republics and remain a major power. Subverted in the subsequent decades which saw a recovery of Russia and the return of it as a great power. How long this lasts, of course, remains to be seen as Russia's actions in Ukraine has attracted the ire of every other Western nation, leading to sanctions and international pressure.
In some sense, Soviet Union was initially this to the Russian Empire. After defeating Napoleon, Imperial Russia dominated the stretch of territory from the English Channel in the west to the Rockies in the east. In the hundred years afterwards, they lost influence over Central Europe, sold off Russian America, and of course fell apart during World War I.
At one time, Croatia was a really good example of this trope. Though not being an empire, but rather an administrative division with certain degree of autonomy within the Habsburg monarchy, the Kingdom of Croatia definitely was this in 1594, at the height of ottoman conquest of Europe. It had been reduced to but a shadow of it's former self. Fortunately it managed to pull itself from the brink due to a spectacular victory in the Battle of Sisak in which some 8.000-20.000 ottoman soldiers were either slain or drowned, whilst croats suffered a loss of mere 50 soldiers. This period also gave birth to a phrase "reliquiae reliquiarum olim inclyti regni Croatiae" ("remnants of the remnants of the once great kingdom of Croatia").