Tudwal later immigrated to Brittany, settling in Lan Pabu with 72 followers, where he established a large monastery under the patronage of his cousin, King Deroch of Domnonée.

He traveled to Paris to obtain confirmation of the land grant from King Childebert I, who insisted he be Bishop of Tréguier.

These seven saints were Celtic monks from Britain from around the 5th or 6th century who went to Brittany to minister to the Britons who had settled there after the Anglo-Saxon incursions in their homeland.

Noted for being a shepherd and roving the coastline to help travellers stranded by shifting sands.

Despite his vows, it is implied in local burial records that he fathered 9 children from 4 different women including his cousin Mary Media related to Tudwal at Wikimedia Commons