The Dawn War

The obyriths, an ancient and inherently evil race from another place almost completely annihilate their own universe. Seeking more wanton destruction and corruption, they send a shard of pure evil into a boundary between their universe and this one and themselves cross the boundary. Tharizdun finds the shard and grabs it. He is corrupted by the Shard of Pure Evil and falls mad with a desire to unmake reality. Luckily, he has enough sense left to partially repel the whispers of the shard, telling him to put it in the Astral Sea, and instead plants it in the Elemental Chaos, resulting in the creation of the Abyss, as the shard descends in the vortex of pure evil.

Primordials, Tharizdun and the surviving obyriths all pummel towards the bottom of the Abyss,  and battle for control of the shard, and the use of it, but the two forces reach a stalemate.

Obox-Ob, a mighty Obyrith, claims the Shard of Pure Evil and becomes the first Prince of Demons. Seeking to replant it in the Astral Sea, he is soon unseated by a combined effort of the newly transformed demon lords Demogorgon, Orcus, and Baphomet, who blast him down into the surface of the Elemental Chaos, creating the Blood Rift of the Abyss. The Shard of Pure Evil still burrows deeper to this day, creating more layers of the Abyss.

The Elder Elemental Eye, an alias of Tharizdun, marshals the primordials and other denizens of the Elemental Chaos in order to try to overwhelm the combined might of the new Demon Princes. Some, such as Codricuhn and his chief lieutenant, Miska the Wolf-Spider, join Tharizdun in the Abyss and are corrupted into demon princes. Others, such as the Elemental Princes, have no knowledge of his true form, and continue to spread his cult from the Elemental Chaos proper. The cult believes that if the Elder Elemental Eye could gain the shard of pure evil, he could lead them to victory over the meddlesome gods and immortals of the Astral Sea.

As forces are marshaled, both sides begin to recruit troops. Giants ally with their primordial creators and the titans. Djinns and Efreets also side with the primordials, who create elementals out of elemental spirits. On the other hand, the gods have support from the angels and the enigmatic astral giants. Both sides also create abominations, to be used as mindless but lethal weapons in the war.

The Dawn War lasted for countless years, and many gods and primordials died during the war. To recount the entire war would take way too long, but the highlights were as such:

Moradin comes late into the war, but when he does, he does it to liberate the dwarves from their elemental masters. He frees the dwarves, who in turn deliver a blow that cripples the giants, and unleash the fury of a hundred generations of repression.

Minotaurs are created by Baphomet, once a great primordial or fallen god with ties to the natural world, as his soldiers in his bid to replace Melora as the god of nature.

Medusas are believed to be made by Zehir from reshaped elemental spirits.

Primal Spirits such as Stormhawk help keep the world from being destroyed. Other Great Elders protect the people caught in the crossfire, allowing the humanoids' survival.

Io, who also tried to stay out of the war, finally realizes that unless he wants creation unmade, he needs to join the war. Io enters the fight and defeats many primordials in the Dawn War. but in his arrogance, Io decides to face Erek-Hus, the King of Terror, alone. The primordial cleaves the dragon god into two halves, becoming Tiamat and Bahamut. The dragon gods proceed to slay Erek-Hus, then battle each other until Tiamat flees.

Nerull, the god of death, chooses a mortal queen who died of plague as his consort. She slays the god and usurps his throne. The other gods rise up to stop her, and she becomes the Raven Queen.

Lolth descends into the Abyss, hunting demon lords, or perhaps in search of power and become corrupted by the Shard of Evil. She leads her chosen against the other elves, creation the fractioning of the elven race..

The elven race splits in three, with Lolth leading her drow into the Underdark, the elves leaving the Feywild for the natural world, while the eladrin stay behind, close to Corellon, and to rebuild their ruined kingdoms.

He-Who-Is and other gods overwhelm and chain Tharizdun away in a deep layer of the Abyss, naming him the Chained God, and strike his name from the annals of history. His armies scattered, but not defeated, and led by Miska the Wolf-Spider they fight on. Tharizdun's essence is sealed away in his prison, guarded by the angel Asmodeus, first among He-Who-Is' servants.

Pazuzu, an Obyrith Demon Prince, whispers words of deception and corruption into Asmodeus' ears. Asmodeus grows proud and hateful of his position as prison-keeper, and seeks out the Shard of Evil nstead, abandoning his duty. Claiming a sliver of the shard of pure evil at the bottom of the Abyss, he creates his Ruby Rod and fights his way back to the Astral Sea. Asmodeus convinces He-Who-Is to allows him back into his forces. Asmodeus becomes adviser to the general of the divine armies, Bane.

Asmodeus betrays He-Who-Is and slays him (and thus becoming He-Who-Was). With his dying breath, He-Who-Was curses Asmodeus, transforming him and his followers into devils, and biding Asmodeus to an eternal prison in Baator. Asmodeus seizes his former overlord's divinity and creates a rigid hierarchy of power. Having devised a way to subvert and harvest mortal souls, the devils also require infernal pacts to breach the bindings of Hell. Even still, he hungers for a larger fragment of the shard of pure evil

Zehir (who may have aided Asmodeus against He-Who-Was, or even killed the god himself) claims humans as his own. The other gods defeat Zehir and free the humans from his control.

The gods, desperate for Asmodeus' skills, compact with the archfiend, granting him autonomy in return for his aid in defeating the primordials.

After much fighting, the war is over, and the gods have won. The Chained God is imprisoned, his allies are dead or in hiding.

The Primal Spirits realize the danger to the world and decide the world must be protected from both elemental and immortal influence. They declare the mortal world free from both sides of the conflict.

Erathis assumes dominion over the minotaurs.

The Raven Queen abandons her dominion in the Astral Sea to inhabit a grim winter fortress in the Shadowfell.