Augustine of Hippo

Born in 354 in Numidia, Augustine drifted through Manichaeism and Neoplatonism before converting to Christianity in 386 under Ambrose. As Bishop of Hippo Regius, he developed a theology of original sin and unmerited grace that would echo through centuries, penned the first Western autobiography in his Confessions, and in The City of God imagined the Church as a spiritual city against the collapse of Rome. He died in 430, leaving works — On the Trinity, On Christian Doctrine, theories of just war — that shaped medieval thought and later fed both Catholic doctrine and Protestant Reformation. Tho…