the foremost Latin theologian of his age. A convert from paganism, he was elected Bp. of Poitiers c.350. He became involved in the Arian disputes and, probably as a result of his defence of Catholic teaching, in 356 was exiled for four years by the Emp. Constantius. In 359 he defended the cause of orthodoxy at the Council of Seleucia. His main works are a treatise De Trinitate (against the Arians); De Synodis, valuable for the doctrinal history of the period; and the so-called Opus Historicum. He is the earliest known writer of hymns in the W. Church. Feast day, 13 Jan. (before 1969, 14 Jan. in the RC Church).