Latin Church Father (c. 310-c. 367) and the principal Western defender of Nicene orthodoxy against Arianism in the post-Nicene period. Born to a pagan Gallic-Roman family at Poitiers; trained in classical letters; converted to Christianity in adulthood through study of the Scriptures (a substantial reading of the Johannine prologue, John 1:1-14, was foundational in his conversion narrative as recorded in De Trinitate); elected bishop of Poitiers around 350. Hilary's principal historical-theological significance is his vigorous defense of Nicene Trinitarian orthodoxy against the Arian-influenced Western imperial-church settlement attempted under Emperor Constantius II (337-361). Hilary refused to subscribe to the Arian-leaning settlement; was exiled to Phrygia in Asia Minor by Constantius II from 356 to 360 (an exile that proved theologically productive for Hilary, as he deepened his engagement with Greek Trinitarian theology and the writings of the Eastern Fathers). Returned to Gaul in 360 after the Council of Constantinople's homoean settlement broke down; resumed his episcopal ministry; continued his vigorous Trinitarian polemic until his death (c. 367). Hilary's principal theological work is the twelve-book De Trinitate (On the Trinity), the foundational Latin Trinitarian treatise of the fourth century. Other works include the Tractatus super Psalmos (commentary on the Psalms, drawing on the Greek tradition of Origen and others); the De Synodis (a substantial treatise on the various synods of the Arian controversy, addressed to the Gallic and British bishops); polemical works against the Arians; and a substantial body of hymns (Hilary is one of the earliest Latin hymn-writers). Sometimes called the Athanasius of the West for his role in defending Nicene orthodoxy in the West parallel to Athanasius's labor in the East.