2521: Archaon leads a massive invasion known as the Storm of Chaos. The sacred mists of Albion are restored. Chaos forces attack key sites of the Great Warding around the world, culminating in assaults on Lustria. On the Isthmus of Pahuax, a Beastmen army destroys the Monument of the Moon and the Monument of the Sun is desecrated. So many key nodes are lost that Chaos powers flood the world and the foresight of the Slann fails. Vashnaar the Tormentor leads an invasion into Lustria. He unites Dark Elves, Beastmen and monsters beyond count. Attacks by Tiktaq'to stall the Chaos invaders long enough for Slann Mage-Priests to wake and defend Hexoatl. By year's end, the temple-city is besieged and likely to fall. Clan Mors Warlord Queek Headtaker is recalled to the City of Pillars in an attempt to bring an end to the ongoing battles there. Elsewhere the copper mines of Grim-Duraz in the Grey Mountains become the latest Dwarf holdings to fall under Skaven control.
2522: Archaon is defeated in single combat by Grimgor Ironhide before the gates of Middenheim. The Chaos army breaks and flees, but goes into hiding in the Middle Mountains. The Empire faces a religious schism as the returned Volkmar and the recently elected Esmer III vie for the office of Grand Theogonist. Dark Elves are seen guiding Chaos attacks. Mazdamundi and Kroq-Gar are forced to return to Hexoatl from Konquata to crush a particularly vicious attack, led by Vashnaar the Tormentor.
2528: Warbands following the Chaos lord Vardek Crom cross Peak Pass and descend into Sylvania. None emerge from its borders, and it is rumored a great Undead army has been raised from their bodies.