Tigernan of Errew, Irish missionary, fl. c. 500-520. In his "History of Mayo" (page 31), Knox writes: "St. Tigernan of Errew worked in Tirawley in the early part of the sixth century. His paten still exists. No more is known of him except he was the founder of Errew Abbey, Lough Conn, County Mayo. The Breastagh Ogham Stone near the king's house of Rathfran commemorates a "son of Cairbre, son of Amalgaid", who may be father or uncle of Tigernan, or a great-grandson of Fiachra Elgach."