Owain Danwyn (Old Welsh Dantguin, also spelled Ddanwyn, Ddantgwyn, etc., meaning "White Tooth"), is known from several medieval genealogies of the kings of Rhos.
[2] Owain was the father of Cynlas Goch, who is identified with the prince named Cuneglasus who Gildas castigated for his various sins in De Excidio et Conquestu Britanniae.
Peter Bartrum suggests this may have been Owain, though he notes that Gildas' term avunculus typically refers to a maternal uncle.
[3] Writers Graham Phillips and Martin Keatman proposed that Owain Danwyn was the historical basis for the legendary King Arthur.
According to Phillips and Keatman, "Arthur" was Owain's honorific title, meaning "Bear", and his capital was Viroconium in Shropshire, England.