The Brethren War was a conflict of various packs of Uratha for territory in North America that soon spiraled out of control. Many of the Forsaken’s oldest and strongest had fallen in a terrible struggle against potent spirit enemies, and the younger packs began to fight one another to claim the prize territories that the elders’ deaths had left unclaimed. The Pure, however, were watching for just such an occasion. They swept down on the Forsaken, who were still battered and bleeding from fighting one another. The Brethren War ended with the Tribes of the Moon being forced to put their internal conflicts aside and repel their enemies as best they could. Yet in the attacks that followed the Brethren War, great swaths of land fell into the claws of the Pure. It was a terrible loss of ground, one that the Forsaken are still fighting to reclaim in places such as the Colorado Rockies, the Midwestern Rust Belt and the Pacific Northwest.
The Brethren War also gave the Idigam a chance to reestablish themselves on the world after being banished to the moon.