According to a Latin Life of Deiniol, preserved in Peniarth MS226 and transcribed in 1602 by Sir Thomas Williams of Trefriw, he was the son of Abbot Dunod Fawr, son of Pabo Post Prydain.
He attended the Synod of Llanddewi Brefi in c. 545 with Saint David when the subject of rules for penance was being discussed.