Morgause

Legends

Morgause is the sister or half-sister of King Arthur in the Arthurian legend. In her earliest appearance she is Arthur's full sister by Uther Pendragon and Igraine; and is the mother of the heroic Gawain and the villainous Mordred. In later works she is the daughter of Igraine by her first husband, Gorlois, and she becomes pregnant with Mordred after sleeping with Arthur while they were unaware of their relation. Her husband is King Lot, an enemy of Arthur in the rebellions following Arthur's coronation.

Her other siblings include sisters Elaine and Morgan le Fay.