https://en.wikipedia.org/wiki/List_of_Arthurian_characters
WebArthur's grandfather, father to Uther Pendragon, Constans, and Ambrosius Aurelianus Constantine III of Britain: Historia Regum Britanniae, c. 1136 Historia Regum Britanniae, Le Morte d'Arthur: Arthur's cousin and successor to his throne, Cador's son Culhwch: Culhwch and Olwen, c. 11th century