"Even in the heart of Heaven...angels can still feel fear."What's the one thing worse than Hell on Earth? When The Legions of Hell decide to invade that most holy of places, Heaven itself! In works that focus on the conflict between Heaven and Hell (which to be fair, includes most works where Heaven and Hell appear as opposing sides) this will be the ultimate goal of Hell, and is usually kept from happening by an Enemy Civil War or other big conflict among the demons, with the major threat being some ambitious demon or other villain seeking to unify them. Oftentimes, invasion of Heaven is an Evil Plan that the heroes need to stop before it comes to pass, similar to Hell on Earth. But for those times when things truly go From Bad to Worse, the demons will launch an all-out onslaught against Heaven, seeking to corrupt or destroy the Council of Angels, the Fantasy Pantheon, or even the Big Guy Himself, with the heroes having the unenviable task of stopping everything from being destroyed (unless God and Satan Are Both Jerks, and the protagonists are Nay Theists and go all "plague upon both your houses, let's Pass the Popcorn and nuke whoever survives"). Since situations like these are nearly always Grand Finale situations, they are usually big spoilers. Compare Hell on Earth and Rage Against the Heavens.
— Leah as Diablo, Diablo III
- This is Hell's grand plan in the Spawn series, with Hellspawn in charge of gathering souls for Hell's army.
- Subverted in Lucifer: Hell first defeats the Lilim, who are besieging Heaven. Although Heaven surrenders to Hell, this is demonstrated to be the correct moral outcome, since the leader of the Hellish host Christopher Rudd is redeemed.
- This is attempted in Ghost Rider's "Heaven on Fire" arc since most of the angels are out of commission, but it still fails horribly as the Spirits of Vengeance fill in for them, resulting in much demon ass getting kicked.
- The Space Opera version occurs in Final Crisis with the New Gods: "There was a war in Heaven and the Dark Side won."
- Wendy Alec's The Chronicles of Brothers series, a series of Christian polemic novels about the in-fighting between the brethren Gabriel, Michael, Christos and the black sheep of the family, Lucifer. The aforementioned Lucifer tries this on more than one occasion, only to be humiliatingly bitch-slapped by his brother Christos and the lads. As Mrs. Alec's novels follow pretty much exactly the Christian perspective and what is "known" (in the Bible and related sources) about the nature of Heaven and Hell and their denizens, you wonder why Lucifer even bothered... it's in the Bible, you'll never win....
- John Milton's Paradise Lost is the trope codifier/forerunner by depicting Satan's rebellion against God.
- The above novel inspired a subverted example of this trope, the His Dark Materials series, where The Legions of Hell are actually the good guys.
- Attempted in the backstory of "The Snow Queen" — the devil invents a magic mirror that will make everything look hideous, and he and several of his student demons decide to take it to Heaven so that they can mock God and the angels. The mirror breaks before they can get high enough.
- In Supernatural, this seems to be Lucifer's PR to his demon mooks after they release him and start the Apocalypse. Meg cheerily taunts a captured Castiel that they're going to win against the angels and invade Heaven itself. In reality, Lucifer wants the demons to have no part in his plans and considers them worthy of annihilation.
- According to the La Llorona mythos believed in by Miami street kids, a demon attack went down in Heaven, and God had to flee. No one has seen Him since, and the angels have to fight off the demons in the meantime. Demons have found a way to invade our world, and the angels who aren't defending Heaven have come to Earth to fight them.
- In Dungeons & Dragons, if the Blood War between the demons and the devils ever ends, the Upper Planes can look forward to a full-scale war with the fiends as they launch an invasion. When the Blood War did end in the Forgotten Realms setting...this didn't end up happening. Asmodeus permanently shoved the Abyss into a corner of the Great Wheel that couldn't reach them, used the resulting chaos to ascend to full-on godhood, and then settled in and started the clean-up process.
- Exalted: In Return of the Scarlet Empress The force of the Demon City or rather, just the Ebon Dragon manages to invade Yu-shan and kills all the Incarnae. What they don't expect, though, is that the death of the Incarnae unlocks the god-tier powers of all Celestial Exalts.
- In The Ring of the Nibelung, Alberich boasts that he will invade Valhalla from Hella once he recovers the Ring.
- This is the final act in the first campaign of Diablo III. Diablo, having become the Prime Evil and the sole ruler of the Burning Hells, leads a massive demonic invasion of the High Heavens. The angels are unprepared for an attack of this magnitude and are quickly overrun. The player helps drive them back and defeats Diablo at the heart of the High Heavens. Supplemental materials explain that similar attacks have occurred in the past but never made it past the Diamond Gates, usually due to demonic in-fighting weakening their forces.
- In Titan Quest: The Immortal Throne, when you reach the Elysium you find out that the heroes there are fighting back the hordes of shades and demons serving Hades, which has gone mad with power. Odder than the standard example because Elysium is still part of Hades's kingdom.
- The final part of Titan Quest also qualifies as a variation; you have to prevent Typhon, the most fearsome of the Titans from invading Mt Olympus.
- In Super Paper Mario, an army of Skellobits from the Underwhere invades the Overthere, where an army of Nimbis rises to fight it. In a twist, said Skellobit army is not affiliated with the leader of the Underwhere who is actually raising a daughter with her Overthere counterpart, but with a recently-released Sealed Evil in a Can who serves as the chapter's boss.
- This is what happens in the True Demon Ending of Shin Megami Tensei III: Nocturne.
- While it doesn't happen literally, this symbolically happens in Persona 4, when the Investigation Team must go through the Shadow-infested dungeon of Heaven, where Nanako is being held.
- This is what the last few levels of Disgaea: Hour of Darkness are based around. You're the one controlling The Legions of Hell. It turns out to have been a part of a plan cooked up between the guy in charge of heaven and Laharl's father to make sure he ends up as a Noble Demon.
- In Planescape: Torment, Trias the Betrayer was planning to organize an army of fiends to do this to get the gods to wake up and deal with the Blood War, which led to his incarceration under Curst.
- The driving plot of Painkiller. Lucifer is using Purgatory as a staging ground from which to launch an invasion of Heaven, and Daniel Garner is Heaven's hitman chosen to send Lucifer's generals back to Hell to slow down Hell's armies while Heaven prepares.
- In the Lady Spectra And Sparky storyline "Demon War", archfiend Melado and his minions invade the Limbo-like afterlife realm of "Rha-Sha-Shama".
- In one episode of South Park, the legions of Hell are invading Heaven and Kenny (who is currently dead) is called on to stop them.
- In the Futurama movie The Beast With a Billion Backs, the living beings in the universe move to Yivo, a kindlly monstrosity whose body is in fact Heaven. Bender misses Fry, so brings his army of damned robots from Robot Hell to attack.