Morgause /mɔrˈɡeɪz/, in the Arthurian legend, is a sister of King Arthur and the wife of Lot, king of Orkney and Lothian. Her sons Gawain and Mordred are key players in the story of Arthur and his kingdom—the latter notoriously the product of her incestuous relationship with Arthur. She is also the mother of Gareth, Agravain and Gaheris.
Read more about Morgause: Earlier Counterparts, Malory's Morgause, Modern Depictions