Bartrum's "Welsh Classical Dictionary". In the Book of Llandaf he appears with his brothers Rhodri, Meurig, and Ffernfael and his father Ithel as witness to a charter in the time of bishop Berthwyn (BLD 191); later with his brother Meurig, who was king, in the time of bishop Terchan (BLD 204). He finally appears as king himself (BLD 211a), king of Glywysing (209a), both in the time of bishop Cadwared. According to J.E.Lloyd Rhys and his brothers Rhodri and Meurig were kings in Glywysing while Ffernfael was king of Gwent (HW 274). Wendy Davies suggests about AD 745-775 for his period of activity as king (LlCh p.76).