Saint Augustine of Hippo was a fifth-century theologian, philosopher, and doctor of the Church. He is one of the most influential figures in the development of Western Christianity and is often referred to as the "Doctor of Grace". Augustine was born in 354 AD in the Roman province of Numidia, in what is now Algeria. He was raised in a Christian family and was educated in the classical tradition of the Roman Empire. He was a brilliant student and eventually became a professor of rhetoric in Milan. Augustine was a prolific writer and his works are still studied today. He is best known for his Confessions, a spiritual autobiography that chronicles his journey from a life of sin to a life of faith. He also wrote The City of God, a work that sought to reconcile the teachings of Christianity with the classical philosophy of the Roman Empire. Augustine's teachings had a profound impact on the development of Western Christianity. He is credited with the development of the doctrine of original sin, the idea that all humans are born with a sinful nature. He also developed the concept of predestination, the belief that God has predetermined the fate of all humans. His teachings on grace and free will have been influential in the development of Protestant theology. Augustine's legacy continues to this day. He is remembered as one of the most influential figures in the history of Christianity and his works are still studied and discussed by theologians and philosophers alike.