戒規
Born in Ireland and raised in Scotland as a young man, he lived the life of a hermit on Holy Isle (off the Isle of Arran). He later visited Rome as a pilgrim and was subsequently said to have been ordained a bishop there. He later entered the monastery at Old Leighlin in Ireland where he became abbot and possibly bishop. He adapted Church discipline in accordance with the practices of Rome. He is credited with introducing or advocating the Roman method of dating the celebration of Easter.