Ambrose of Milan

Born around 339/340 in Trier, Ambrose served as governor of Liguria and Aemilia before being acclaimed Bishop of Milan in 374, despite not yet being baptized. He became one of the most influential figures of Western Christianity of his time, steadfastly defending Nicene orthodoxy against Arianism, especially against Emperors Valentinian II and Theodosius I. A prolific theologian and writer, he authored numerous moral, exegetical, and dogmatic treatises, and is also recognized for his role in the development of Latin hymnody. He played a crucial role in the conversion and theological formation of Saint Augustine of Hippo. He died on April 4, 397, and is one of the four original Latin Doctors of the Church, along with Jerome, Augustine, and Gregory the Great.