Morgan la Fay
From Conservapedia
In legend, Morgan la Fay was the head of the order of virgin priestesses who guarded the Holy Grail on the Isle of Avalon and who later received the mortally wounded King Arthur after the Battle of Camlann. Some stories state that Morgan la Fay was actually King Arthur's sister, which is possible, but a few even state that Mordred, Arthur's nephew and enemy, was actually Arthur's son by an incestuous liaison with his sister Morgan. Other stories state that she had another sister, Maeonia, who was a temple prostitute and that it was Maeonia who was the true mother of Mordred.