Saint Peirio was a 6th-century pre-congregational saint of Wales and a child of King Caw of Strathclyde. Biography In 605AD he founded a church at Rhosbeirio on Anglesey Island, North Wales. Writing in 1861, Harry Longueville Jones said of St Peirio's church that it was "one of the humblest ecclesiastical buildings in Anglesey" and that there were "no architectural features in this church worthy of delineation." References Medieval Welsh saints 6th-century Christian saints 5th-century Welsh people 5th-century births Roman Catholic monks Welsh Roman Catholic saints Year of birth unknown Year of death unknown Christian female saints of the Middle Ages