Ruler of Caledon, son of Cyleddon, and father of Culhwch. Cilydd married Goleuddydd, sister of Igerne (Igraine).
His wife was mortally wounded giving birth to Culhwch, and on her deathbed she made Cilydd promise not to remarry until he saw a two-headed briar (thorn) growing on her grave. She had prearranged to have the grave stripped each year.
He did not see such a thorn until seven years later, at which time he sought another wife. He found a suitable woman in the wife of King Doged. Cilydd killed Doged and brought Doged’s wife back to his court.
Kilwydd | The Legend of King Arthur
Culhwch and Olwen | Late 11th century