Hilary of Poitier was a Bishop in western France in mid-fourth century. He is one of the first Trinitarian Theologians who would be able to pass later orthodox standards. He plays a very interesting role in the history of the fourth century. We mention Athanasius of Alexandria, Arius of Alexandria, Constantius, Constantine the Great, Julian the Apostate, Martin Luther, John Calvin, Michael Servetus, Karl Barth, and more.