Hilary

Hilary of Poitiers (Hilarius Pictaviensis) was a fourth-century bishop of Poitiers and later Doctor of the Church, remembered as the principal Latin opponent of Arianism in Gaul. He was born at Poitiers in Roman Aquitania to a family of pagan notables; the precise year is not recorded. He received a classical education in Latin letters and philosophy. As an adult he converted to Christianity after study of Scripture, an event later writers connected especially with the prologue of the Gospel of John. Before his elevation to the episcopate he was married and had a daughter, Abra (also called Apra), who is commemorated as a saint in some local traditions. About the middle of the fourth century the clergy and people of Poitiers elected him bishop, an unusual choice of a married convert rather than a cleric formed in the usual cursus.

As bishop he became a leading defender of the Nicene confession against Arian teaching, which then enjoyed imperial support under Constantius II. In 356 an Arian-dominated synod at Béziers condemned him, and the emperor exiled him to Phrygia in Asia Minor. During roughly four years in the East he composed his chief theological work, the twelve books of De Trinitate, together with polemical and historical writings such as the Liber adversus Valentem et Ursacium, and some of the earliest surviving Latin hymns. He attended the Council of Seleucia in 359. Allowed to return to Gaul around 360, he resumed his see, worked to restore displaced Nicene bishops, and continued to contest Arian incumbents in the West, including Auxentius of Milan.

He died at Poitiers; later chroniclers most often give the year 367, though 366 and 368 also appear. He was buried in the city, and the church that became Saint-Hilaire-le-Grand was the centre of his cult. Veneration is already attested in the fifth century; Venantius Fortunatus wrote a life of him, and his feast entered Western calendars. In 1851 Pope Pius IX declared him a Doctor of the Church in recognition of the lasting importance of his Trinitarian theology for the Latin tradition. His feast is kept on 13 January in the General Roman Calendar (formerly 14 January). He is invoked as patron of lawyers, reflecting his role as a public defender of doctrine, and of the city of Poitiers. His writings influenced later Western Fathers, notably Ambrose and Augustine, in the development of Latin Trinitarian language.