The Riftwars

The Riftwars were a series of wars fought between an alliance of eastern men called the Shining Crusade and the hordes of demons and undead forces of the Demon-Lord Khellum-Zhûr.

Khellum-Zhûr was eventually defeated by Arazni at the famous Battle of Three Sorrows, and driven into the Blight. Once there, the champions erected the Boundary; a powerful magical barrier to keep out the demonic forces. For the last three-thousand years, the Boundary has largely held, although demons and undead sometimes get through.