B. c.1160, s. of Owain Cyfeiliog; acc. 1195; m. Margaret, da. of Robert Corbet; issue: Gruffydd, Madog; d. 1216.
Gwenwynwyn took over from his father in southern Powys in 1195 and added the lordship of Arwystli to the south in 1197. He made an early bid for pre-eminence among the Welsh princes, launching a series of attacks upon marcher territories. He seems to have overplayed his hand, and in 1208 John deprived him of his kingdom. Restored in 1210, he was forced into a dependence upon Llywelyn ab Iorwerth. This broke down in 1216 and Llywelyn soon pushed him into exile in Cheshire, where he died.
Subjects: British History.