 As such, he was a prince in both the kingdoms of Glywysing and Gwent as his cousin Athrwys was king of Gwent.He became King of Glywysing in 785 succeeding his father Rhys ap Ithael.He married the daughter of Braustud ferch Glowd of the Kingdom of Buellt, with whom he had two sons Rhys ap Arthfael and Meureg ap Arthfael.