Austol was a 6th-century monk of Cornish origin who spent much of his life in Brittany. He maintained a close friendship with Mewan, the founder of Saint-Méen Abbey, who is also believed to have been his godfather. Historical accounts suggest that Austol passed away only a week after Mewan died. Because of the deep bond between these two figures, their respective parishes in Cornwall and Brittany traditionally celebrated their feast days together before the Reformation.