 He founded a monastery at what is now Tréguier but when called back to Wales because of a terrible plague there, he left his nephew Tugdual in charge.When he returned he found Tugdual totally in control and set off along the Léguer estuary, landed where Saint-Brieuc stands today and founded a monastery after firstly setting up a modest oratory.Later he had the first cathedral built and took the role of bishop for himself.