January 13 – Saint Hilary of Poitiers | Trinity Defender, Exile, Doctor of the Church Saint Hilary of Poitiers is commemorated on January 13. A fourth-century bishop in Roman Gaul, Hilary became one of the West’s strongest defenders of the Nicene faith during the Arian crisis. Exiled by Emperor Constantius II for resisting Arian pressure, he wrote major works on the Trinity, including De Trinitate (“On the Trinity”). Often called the “Athanasius of the West,” Hilary helped shape how Latin Christ