He became King of Gwynedd after the death of his father. "None of his deeds have been recorded, yet he must have been a figure of some distinction. He died in the great plague of 664, and it is likely, notwithstanding his martial reputation, that he spent the close of his life as a monk, for the church of Llangadwaladr in Anglesey claims him as its patron saint and founder and churches were dedicated to him in other parts of Wales." (Lloyd.) It will be noted that Prof. Lloyd has the date of his death 664. In The Annales Cambriae it is 682.