British delegates participated in the ecclesiastical councils of the period of Roman occupation the Synod of Arles in 314 and that of Rimini of 359, but this participation ceased in the 5th and 6th c. During the time of the Roman occupation of Britain, Roman missionaries converted Wales, Iran Map which became thoroughly Christian through the work of Celtic missionaries in the following three centuries. Accounts of a pilgrimage to Palestine center on St. Teilo, bishop of Llandaff in the 6th c. St. Deiniol lived during this century and was considered the first bishop of Bangor. Also in the 6th c., St. Asaph became a disciple of Kentigern while exiled in Wales and later became head of the monastery and bishop of Llanelwy, later called St. Asaph. St. David d. 601 was certainly a disciple of Iltut, a Breton soldier of fortune in the service of the king of Glamorgan, converted after meeting the Christian hermit Cadoc. David distiguished himself as the founder of monasteries in the tradition of the Egyptian desert. He may have participated in the Synod of Brefi in ca. 520, and it is said that he called a council at Caerleon Lucus Victoriae in 569, of which no texts survive. The Celtic bishops met Augustine of Canterbury in ca. 603, but submission of the Welsh churches to the see of Canterbury came about slowly a few centuries later. They remained turned toward the past, with strong regional characteristics, until the Norman conquest. For example, they did not adopt the general practice of the celebration of Easter, or other aspects of ecclesiastical discipline, until 768.