Petroc himself would have lived much later than King Arthur; however, his namesake St Petroc, with which he is often confused, was described as one of the seven survivors of the Battle of Camlann according to Evan Evans’ copy (Panton MS 13) of the 17th-century Peniarth 185 manuscript.
In 518 he welcomed the Irish monk, St Petroc, who was seeking to found a monastery in the area, which he did near Padstow.
In Wales his name is commemorated at St Petroc near Pembroke, Ferwig near Cardigan and Llanbedrog on the Lleyn peninsula.