Xoriat

Xoriat, called the Realm of Madness, is a plane beyond description. By merely visiting the plane, non-natives risk having their minds shattered at the sight of the chaos. It is the home of the daelkyr. Over 9,000 years ago, Xoriat became coterminous with Eberron, and the continent of Khorvaire was overrun by the daelkyr and their aberrations. This started the Daelkyr War. The daelkyr destroyed the Dhakaani Empire, but were pushed back to Xoriat by the Gatekeepers. Dimensional seals created by the magic of the Gatekeepers, with the help of the dragon Vvaraak, have disturbed Xoriat's orbit, preventing it from becoming coterminous again. Since then, the Gatekeeper druids patrol the seals to Xoriat, making sure that no abominations return to Eberron. However, not all daelkyr were pushed back, and many of them were sealed in Khyber.