Saint Augustine (354-430), born in Thagaste in Numidia (present-day Algeria), is one of the greatest Christian theologians and philosophers. After a youth marked by spiritual wanderings, he converted to Christianity under the influence of his mother, Saint Monica, and Saint Ambrose. Having become Bishop of Hippo, he wrote major works such as The Confessions and The City of God, which profoundly influenced Christian thought. Defender of the faith against heresies, he was proclaimed Doctor of the Church. Died in 430, his feast day is celebrated on August 28.