Cousin of King Deroc of Dumnonia. Monk in Wales. Friend and co-worker with Saint Briarch. Evangelized in Brittany. Founded the monastery of Lan Pabu at Leon, Spain. Bishop of Tréguier (Treher), Brittany. Advisor to King Childebert I. Several sites in the Leyn Peninsula of Wales bear his name.
- “Saint Tudwal of Tréguier“. CatholicSaints.Info. 28 November 2010. Web. 30 June 2015. <>