Falls of Despair

The Draesca tribe dwells near the mines of Oakenhammer, in the mountains to the far south of Sylvania. During each tribal coronation, the new High King will don the Helm of the Draesca: an ancient artifact that accelerates the aging process of its wearer dramatically. Seven years of twilight are granted to the King before he finally succumbs to undeath altogether. During that time, his every whim is catered for-the helm grants him great power over the living and the dead alike. Each new High King is determined to carve his mark on the world before his tenure has passed, and so the armies of the Draescan Kings go forth into the world every seven-year cycle, their numbers bolstered not only by thousands of the living dead but by the dusty cadavers of every king to have ever worn the helm.

Source

 * : Warhammer Armies: Vampire Counts (8th Edition)
 * : pg. 29