excerpt from the history of eberron:
The Qabalrin were a reclusive sect of elves whose arcane might even the giants feared, and these elves lived alongside their drow cousins, who they employed as servants and arcane assistants. Stories tell of how the titans first learned their magic from the dragon god Ouralon, bringer of light and law, even as the Qabalrin drew on the power of Ouralon’s terrible divine Shadow. Whatever the truth behind the legends, these elves were the mightiest conjurers and necromancers Eberron had ever seen, pioneering many of the necromantic techniques used in the present day—along with most of the fundamental principles of the necromantic religion that would one day become known as the Blood of Vol. According to legend, the Qabalrin created the first vampires, some of whom might still lie entombed in their ancient ruins.
The Qabalrin lived in a single massive city-state called Qalatesh, a fortress in the legendary mountainous region of Xen’drik known as the Ring of Storms. Left unchecked, the Qabalrin might have one day dominated the land, but fate—or divine providence— intervened. Over forty thousand years ago, a massive Siberys dragonshard called the Heart of Siberys plummeted from the sky, smashing into Qalatesh. The impact and the resulting devastation (both magical and natural) destroyed the necromantic elves’ civilization. Remarkably, though, the damage did not extend beyond the mountain ring. The giants called this outcome a miracle, citing the harsh justice of Ouralon and the event as a divine warning to those who would traffic with the Shadow.