The Battle of Skull Gap

War was inevitable. The Legion of Bone struck first, driving the Sheaim mages into the depths of the Red Pyramid, where they laid siege. After one year and a day, the sheaim emerged from the Pyramid leading an army of tens of thousands of powerful demons, and the Legion of bone was routed.
The two empires collected their forces and met at the Battle of Skull Gap. Both were obliterated, as were the ancient Norlord fortresses along the Towers of Dawn.
the survivors returned home to open rebellion. The charismatic Sorceress of Helios united the former Norlord kingdoms in the west and became the Empress. Dregloth was too weak to challenge her authority, the victim of internecine battles between their own necromancers. The kingdoms of Teng and Maru-Qat revolted against the mages of Sheaim in the east, but the true death blow to Sheaim came when the headstrong demons they summoned broke free of their bonds, slaying their former masters in all-out intestinal warfare. Only two Sheaim cities survived intact, Magedoom in the north and Blackspire in the south.