By 1606, all Anhalt principalities had turned to the Reformed faith, however, Anhalt-Zerbst returned to Lutheranism in 1644. In 1667, Prince John VI inherited the remote Lordship of Jever in East Frisia. Upon his death in the same year, however, Anhalt-Zerbst lost more of its territory, with Anhalt-Mühlingen and Anhalt-Dornburg being created. The Jever lordship was administrated by Ascanian relatives, it was hit hard by the Christmas Flood of 1717.