The holy Hierarch Hilary was born of pagan parents in Gaul and was trained in philosophy and rhetoric. At a time when paganism was still strong in Gaul, Saint Hilary understood the falsehood of polytheism and became a Christian and a great defender of his new Faith.
About the year 350, he was ordained Bishop of Poitiers when Arles and Milan were in the hands of the Arians and the Arian Constantius was sole Emperor. Like his contemporary Saint Athanasius, Saint Hilary’s episcopate was one long struggle against the Arians. As bishop of Poitiers, Saint Hilary foresaw the future greatness of Martin (see Nov. 12), and attached him to himself.
In 355, when required to agree to the condemnation of Saint Athanasius passed by the Council of Milan, Hilary wrote an epistle to Constantius convicting the wrongs done by the Arians and requesting, among other things, the restoration of the Orthodox bishops, including Athanasius. For this, Hilary was banished to Asia Minor, where he wrote his greatest work, On the Trinity.
Saint Hilary returned to his see in 360, where Saint Martin sought him out again. It was this time that Saint Hilary blessed Martin to found a monastery near Poitiers, where Martin remained until being consecrated Bishop of Tours in 371.
In his last years, Saint Hilary strove for the deposition of Auxentius, the Arian Bishop of Milan, but by affecting an Orthodox confession Auxentius retained his see. Saint Hilary reposed in peace about the year 368. Auxentius died in 374 and was succeeded by Saint Ambrose, who continued Saint Hilary’s battle against Arianism.