Augustine of Hippo, also known as SAINT Augustine, was a theologian and philosopher from the 4th century. He is best known for his Confessions, which is an autobiographical work detailing his spiritual journey. He is also known for his writings on the doctrine of original sin, which he called 'peccavi'. He was the son of SAINT Monica, who is remembered for her unwavering faith and prayers for her son's conversion to Christianity. Augustine is also known by his Latin name, Aurelius Augustinus, or simply DEI.