According to Geoffrey of Monmouth, Ygerna or Igraine (Eigr in Welsh) was the Duchess of Cornwall, ravishing wife of Gorloisand mother of King Arthur. After the death of Gorlois, she married Uther Pendragon, who, under false pretenses and aided byMerlin's trickery, had slept with her, impregnated her with Arthur and had been responsible for her husband's death. Chretien de Troyes claims that after Uther's death, Ygerna retired to a palace she had had built for herself known as the Chastel des Merveillesor "Castle of Wonders".
She was the daughter of Amlawdd Wledig (the Imperator), a member of a younger branch of the Royal House of Dumnonia. He was probably a nobleman of Ergyng, though he has also been attached to the North of Britain and Brittany. His family are central to the Mabinogion story of "Culhwch and Olwen". As well as Arthur, various sources have attributed Ygerna with several children by her first marriage: daughters Elaine, (Anna)Morgause and, perhaps mistakenly, Morgan; sons Gormant and, mistakenly, Cador.