The life of St Hilary of Poitiers
He soon became one of the most forceful Western opponents of Arianism, the teaching that denied the Son's full and eternal divinity, which the emperor Constantius the Second himself favored. For refusing to condemn Athanasius of Alexandria, the great defender of Nicene orthodoxy in the East, Hilary was banished to Phrygia in Asia Minor for some four years.
He turned his exile to good use, studying Greek theology at its source and writing, most notably, a lengthy treatise on the Trinity that became one of the first works to carry the debates of the Greek East into Latin for Western readers. He returned to his see in 361 and continued to teach and write until his repose in 367 or 368, sources giving both years. Among his own disciples was the young soldier who would become Martin of Tours. Hilary is remembered as one of the great teachers of the Western Church in the age of the Trinitarian controversies.
