The War of Heavens & Hells lasted from 534 BR to 466 BR when Krros tried to invade the Heavens.
Krros leads the hells into a war against the heavens and Jakuna, as the boundaries between the two are lessened by the realmshatter. In 466 BR, Krros is struck down back to the hells by Jakuna, ending the war between the gods.