Queen Ygraine Pendragon (née de Bois) was Queen of Camelot through her marriage to King Uther Pendragon, but died giving birth to their son, Arthur Pendragon. She unknowingly became the stepmother of Uther's secret daughter Morgana Pendragon. Whether Uther's affair with Morgana's mother, Vivienne, was before or after his marriage to her is unknown. She was the younger sister of Tristan and Agravaine, and posthumously became the mother-in-law of Guinevere Pendragon through her son's marriage.