Hilary of Poitiers

Hilary of Poitiers (c. 310–367) was bishop of Pictavium (modern Poitiers) in Gaul and the foremost Latin defender of Nicene orthodoxy in the fourth-century Arian controversy, earning him the epithet "Athanasius of the West." Born to a pagan family, he converted to Christianity as an adult and was elected bishop by popular acclaim around 353, reportedly while still married with a daughter named Abra. His magnum opus, De Trinitate, a twelve-book systematic defense of the consubstantiality of the Son, was begun before his exile and completed during it; it became the definitive Latin Trinitarian synthesis and shaped all subsequent Western theology on the subject. Exiled to Phrygia by the Arian emperor Constantius II from about 356 to 360, he used those years in the East to study Greek theology, write De Synodis, and attend the Council of Seleucia (359), before Constantius himself dismissed him back to Gaul around 360 as a nuisance. He was declared a Doctor of the Church by Pope Pius IX in 1851.