St. Augustine
St. Augustine (354–430) was the son of St. Monica. He was raised as a Christian originally, but gave up religion, and was educated at Carthage. In his Confessions, he tells of an untamed youth, during which he became a father to an illegitimate son.
St. Augustine went through a number of philosophical changes, studying neoplatonism and skepticism, until he finally turned back to Christianity and was baptized on Easter, 387 CE. He was chosen to become a priest, which he eventually accepted—later becoming bishop of Hippo (which is in present-day Algeria).
Augustine was famous for his Confessions, both as a source for his own biography and as a story of a conversion to Christianity. He is also famous for his defense of Christianity against early critics in City of God.
St. Augustine's feast day is August 28.