From the LCMS website:
Augustine was one of the greatest of the Latin church fathers and a significant influence in the formation of Western Christianity, including Lutheranism. Born in A.D. 354 in North Africa, Augustine’s early life was distinguished by exceptional advancement as a teacher of rhetoric. In his book Confessions he describes his life before his conversion to Christianity, when he was drawn into the moral laxity of the day and fathered an illegitimate son. Through the devotion of his sainted mother Monica and the preaching of Ambrose, Bishop of Milan (339–97), Augustine was converted to the Christian faith. During the great Pelagian controversies of the 5th century, Augustine emphasized the unilateral grace of God in the salvation of mankind. Bishop and theologian at Hippo in North Africa from A.D. 395 until his death in 430, Augustine was a man of great intelligence, a fierce defender of the orthodox faith, and a prolific writer. In addition to the book Confessions, Augustine’s book City of God had a great impact upon the church throughout the Middle Ages and Renaissance.