The Evil Army is about to overrun our stronghold! Hold the Line tactics worked just fine until The Dragon showed up and smashed a bloody great hole in our defenses. It looks like the enemy has won... but wait! The wizard has finished that spell he was working on! There's a horn sounding over the horizon.
Wait... why are all our fallen comrades in the courtyard stirring? Is that army coming over the hills... translucent?
The essence of this trope is: Fallen allies, usually having died either in the battle at hand or in a previous battle with the same enemy, rise temporarily from the dead en masse and contribute to the ongoing battle in some critical way. The undead in question are more likely to be spectral than physical, but both are possible. The important part is that the loyalty of the fallen is preserved. Also, the army of the dead can help win the (usually climactic or highly significant) battle, but they can't then join the standing army. They tend only to last until the immediate threat is vanquished.
See Also: The Cavalry, Big Damn Heroes, Desperation Attack. Contrast Animate Dead, and Night of the Living Mooks, where the original loyalty of the raw materials isn't relevant. If the dead in question died in different time periods, they may also be an Army of the Ages. Related to The Wild Hunt. For villainous example, see Necromancer and The Undead.
ENDING TROPE! Unmarked Spoilers ahead.
- In Saint Seiya, Hades brings back to life fallen Gold Saints of Athena, granting them 12 hours to bring him her head. If they do so, he may bring them back to life for real. It turns out that they remained loyal to their Goddess nonetheless and only accepted Hades' deal to warn her about the upcoming Holy War while killing some members of Hades' army in the process. Once the 12 hours delay expired, they disappeared to return to the Underworld (where they join again to fire a super Combined Energy Attack).
- In Fate/Zero, among the Noble Phantasms owned by Servant Rider, Alexander the Great, is his Reality Marble: Ionioi Hetairoi, "Army of the King". After the boundary field is set, his entire army from life slowly appear, each and every one so ferociously loyal to Alexander that death itself can not keep them from aiding their king. 100 of the greatest assassins in history? Meet the army that conquered the world.
- Hijikata Toshizo from Drifters is a villainous example of this trope. While a ruthless and brutal combatant on his own, he gets more dangerous when he uses his power to summon the ghosts of the Shinsengumi to fight on his behalf.
- Back in The Invincible Iron Man 150, Iron Man and Dr. Doom were time displaced to Camelot, and met King Arthur. But Dr. Doom was not interested in him, but in King Arthur's sister: Morgan Le Fey. Doom wanted Le Fey to train him into the black magic, and Le Fey requested in exchange that Doom led an army against King Arthur (a spell prevented her from leaving the castle herself). She had a piece of the Excalibur sword, which allowed her to raise an army composed of all those who died by that sword and wanted vengeance against its wielder.
- In Fables #150, Rose Red summons the Knights of the Endless Table: soldiers from every world, and every time and battle who have one thing in common. They all died while holding out hope.
- The film of The Lord of the Rings, as noted above, has the Army of the Dead, led by Aragorn, sweep in and save the day.
- In Deathstalker and the Warriors from Hell, Deathstalker is able to beat the evil overlord Troxartes with the help of an army of undead warriors. Well, technically he talked Troxartes' undead warriors into switching sides.
- The Mummy: Tomb of the Dragon Emperor. The final battle is between the titular Emperor's army of terracotta soldiers, a smaller army of skeletons that's brought out from under the Great Wall of China, a pair of warplanes, and a group of yetis.
- The 1993 film The Ghost Brigade (also known as "The Killing Box") involves a horde of zombified soldiers (reanimated by an evil voodoo spirit) roaming around the forests of Civil War America killing soldiers of both sides (usually targeting whichever side is currently winning the battle first) and taking them to bolster their numbers. The protagonists are a bunch of Union and Confederate soldiers that have to band together to survive.
- In the The Dresden Files book Grave Peril, Harry Dresden raised an army of ghosts against Bianca, assisted by her tearing of the veil.
- Happens again in Ghost Story, when self-styled "Ectomancer" (ghost therapist) Mortimer is suspended in a pit full of shades, and naturally gets control of them.
- In J. R. R. Tolkien's The Lord of the Rings, the Dead of Dunharrow, who over three thousand years ago betrayed Isildur by running away and not coming to his aid against Sauron, are called upon by his descendant Aragorn to fulfill their oath so that they are allowed to pass peacefully into death afterwards. They are released after defeating the fleet of Umbar coming up the river Anduin. This stops Sauron getting reinforcements at the Battle of Minas Tirith, frees the now unoccupied South Gondorian soldiers, and conveniently provides transport to get them up the river to Minas Tirith to once again turn the tide of the battle. While the film version (see above) has them actively fight, here it is unclear if they can fight or if they just terrified the corsairs into leaving.
- Subverted in The Zombie Survival Guide. The Japanese and Soviets both attempted to create armies of undead to unleash upon their enemies. It didn't work.
- At the end of The Princess and the Bear, the animal magic brings all the dead soldiers on the protagonists' side back to fight.
- In Micah E. F. Martin's The Canticle, any Necromancer or High Dead worth his salt has a legion of starving ghouls at their beck and call.
- In the climax of Harry Potter and the Goblet of Fire, the shades of the last several people Voldemort murdered come out of his wand and swarm him, giving Harry just enough time to escape.
- In the last book of His Dark Materials, Lyra and Will have to travel through the land of the dead, and dead characters from the last several books decide to come along with them to help Lord Asriel's side in the fight against The Authority's angels.
- In The Bible, Ezekiel, with God's help, raised his own army of the dead.
- Night Huntress novel At Grave's End sees Mencheres raise wraiths from the powdered bones of the good guys' fallen friends. They are the embodiment of the rage that lingers in the bones of murdered people, and when he releases them, they immediately seek out the one responsible for their death, showing where she is hidden, as well and taking out her guards and tormenting her until Bones arrives to finish her.
- In Warrior Cats, all the villains who die go to the Dark Forest, which is essentially cat hell. An important Myth Arc is that the Dark Forest is rising because of the birth of the Three, and will soon become a villainous variation of this. In the series Grand Finale, The Last Hope, the Dark Forest invades, but the two Heaven equivalents, StarClan and the Tribe of Endless Hunting, fight alongside the Clans to even the odds. This also allows the characters to reunite with their fallen comrades.
- The Wheel of Time has the Heroes of the Horn, legendary heroes who have become bound to the Wheel of Time by their famous deeds; they're meant to be summoned by the Horn of Valere at the Last Battle. There are only about a hundred of them, but the psychological effect of a glorious band of fearful warriors wreathed in mist is enough to bolster the morale of the armies of the Light and give pause to their enemies.
- Provides a Moment of Awesome at the climax of Warbreaker. The villians have seized control of Hallendren's army of 40,000 zombie soldiers, changed the magical control codes to lock out the heroes, and then sent them to invade the heroes' homeland of Idris. At this point, Vasher saves the day by giving the heroes the command codes for the D'Denir, an army of a thousand skeletons encased in stone statues.
- The title army in An Army of the Dead, the members of which not only resurrected in order to defeat an otherwise unstoppable invading horde, they are deliberately killed in order to do so. Seriously hardcore.
- In Dora Wilk Series, Witkacy beats Viola by empowering ghosts of all people she's killed and letting them loose on her. And she's been killing people for a looong time.
- Watership Down sees Fiver calling up the spirits of the rabbits Vervain has murdered when Vervain comes to kill him. It doesn't go great for Vervain.
- In Toll the Hounds, book eight of the Malazan Book of the Fallen, everyone who ever died is marched out of the Warren of Death and into the Warren within Dragnipur right when the forces of Chaos are about to devour those few still dragging the wagon within. The Army of the Dead swoops in and closes with the forces of Chaos just in time to save the day.
- Dr. Greta Helsing: Invoked in the Paris Catacombs when the fight against the Big Bad Corvin and his vampire coven turns against the protagonists. Unfortunately for Corvin, the coven desecrated a lot of bodies to make their lair, and Greta's allies include two Psychopomps who offer the affronted spirits a chance to vent their displeasure.
- Sabaton: The song "The Attack of the Dead Men" from "The Great War" Concept Album about World War I plays up the historical counter-attack by Russians through Deadly Gas without gas masks as if they really were fighting on in undeath.
- Stan Ridgway's "Camouflage" (also covered by Sabaton ). A Marine PFC gets trapped by the Vietcong on patrol, but is rescued by another Marine nicknamed Camouflage. They fight their way out and Camouflage drops the PFC at his HQ, but when he reports to his CO a medic informs him that Camouflage died of combat wounds the previous night.
But before he went, he said Semper fi and said his only wish
Was to save a young Marine caught in a barrage.
- Age of Mythology:
- When you lose normal army units while playing as the Greeks worshiping Hades, you will receive weak "shade" units at your temple. They're weak and vulnerable, but they don't count toward your Arbitrary Headcount Limit, making them great for a Zerg Rush or as last-ditch Cannon Fodder.
- There's also a God Power, Ancestors. It summons a bunch of zombies to fight your enemies, but only for about a minute.
- Also, there's the Einherjar, if you're Nordic.
- In Phantom Brave, Marona's power is to communicate with spirits, and give them corporeal form, basically making an army once you make enough Player Mooks.
- Spellforce 2 Paladins, on their deaths, turn into killable ghost warriors who fade over time. They're only slightly weaker than the original unit, so they're useful for pressing an attack or covering a retreat.
- In Warcraft III, Paladins and their evil counterparts, the Death Knights, both have the ability to resurrect dead units en masse. The main difference is that the Paladin fully restores 6 units to life permanently, but only friendly units, while the Death Knight summons up shades of the most powerful allied or enemy units for 40 seconds, and those shades are indestructible during that time.
- In World of Warcraft, the ability is actually called "Army of the Dead"! However, the way it works changed significantly, most likely due to the Genre Shift from a RTS to a MMORPG. The World Of Warcraft version of the ability simply summons 10 ghouls from the ground to fight for the Death Knight for a limited time. It doesn't require nearby corpses, and the ghouls mindlessly swarm the area and don't have any special abilities, but the spell can still be a very effective "panic button" in some situations.
- In The Battle for Middle-Earth, with units and powers based on the Peter Jackson films, one of the Tier 4 Ring Powers for Men is Army of the Dead, which... summons an army of the dead. Aragorn gets a smaller version of this as his Level 10 ability.
- In Dwarf Fortress, this happens when a necromancer gets into your corpse stockpile. Luckily, Dwarf Fortress players tend to consider magma to be the answer to everything, including cleaning up their junk.
- The Elder Scrolls
- The Dunmer (Dark Elves) practice significant ancestor worship in their religion, believing that their ancestors stick around to watch over their living kin. On a relatively smaller scale, they've summoned the bodies and spirits of their honored ancestors as guardians and protectors for ages. They consider this practice different from true necromancy, which they consider absolutely blasphemous (as seen prominently in Morrowind). Then, during the Oblivion Crisis, they resurrected the massive skeleton of an Emperor Crab (large enough to hold an entire city district inside its shell) to fight back against the Daedric hordes.
- King Gortwog of Orsinium, home of the Orcs who (as the Orsimer or "Pariah Elves") who seem to be eternally Fighting for a Homeland, was said to be considering whether to hire necromancers to supplement Orsinium's forces with the dead against their many powerful enemies. No word on whether or not he went through with it, but Orsinium itself would fall during the Time Skip between Oblivion and Skyrim.
- In the series' backstory, Queen Potema of Solitude (known as " the Wolf Queen") caused one of the bloodiest wars to ever hit Tamriel in an attempt to get her son proclaimed as the rightful heir to the Imperial throne. After her armies and those of her allies were defeated, she held out in Solitude in a protracted siege which lasted 10 years. During that time, Potema, a powerful necromancer and practitioner of other Dark Arts, resurrected many dead bodies to bolster her dwindling forces.
- In Fate/Grand Order, the aforementioned example with Iskandar appears with his Ionian Hetairoi and another appears in the form of Darius III, his "rival" in life summoned as a Berserker, with his Noble Phantasm Athanaton Ten Thousand, "Immortal Ten Thousand Soldiers". His summons his own army to battle, but unlike Iskandar's who are brought forth in their prime, his are an army of ten thousand skeleton warriors, complete with his own personal skeleton War Elephant.
- The Order of the Stick does this during The Siege of Azure City. The Sapphire Guard swore an oath to protect the Gate regardless of circumstances, and even in death, their founder called them back to fulfill their oath. They were more of a major annoyance to the Big Bad, but their leader is a whole different level, and we get to see him deliver a much-deserved curbstomp to both the Big Bad and his Dragon. Unfortunately, due to various reasons however, it failed to completely eliminate the threat.
- DM of the Rings Deconstructs this trope. (It also parodies this trope, of course, just like everything else in LOTR.) Commanding elite undead warriors is almost always evil, or at least looks that way, and relying on anyone bound to serve you by a curse is Playing with Fire. Specifically, be careful of the Curse Escape Clause.
- Used by both sides in the Olympics plot of DC Nation. To be fair, they were fighting Hades. Jerkass God he is, he killed off Nightwing and Arsenal, then sends an army of undead rogues, skeletons, and victims. Just when it looks like the heroes are up a creek, here comes Hawkman, flanked by the two fallen Titans and bringing in fallen allies for one Climactic Battle Resurrection.
- Danny Phantom:
- Depending on whether or not the ghosts are actually the spirits of the dead, the series' finale featured one of these, when Danny recruits the population of the Ghost Zone to turn the Earth intangible and save it from a doomsday asteroid that's heading straight for Earth,
- Pariah Dark's skeleton ghost army in Reign Storm.
- In Futurama The Robot Devil, at Bender's request, assembles for him The Army of the Damned. Though his robots aren't really "dead", they are from Robot Hell.