Hilary of Arles, Saint (hĭlˈərē, ärl) [key], d. 449, Gallo-Roman churchman. Forsaking riches, he entered the monastery at Lérins. He was made archbishop of Arles (c.429) against his wishes. As head of the church in Gaul, Hilary hastily deposed two bishops. They appealed to Pope Leo I, who thereupon deprived the see of Arles of its metropolitan powers, declaring the sovereignty of Rome. Later, Leo referred to him as "Hilary of sacred memory." Feast: May 5.