Augustine of Hippo (Aurelius Augustinus Hipponensis, November 13, 354 - August 28, 430), also known as Augustine, St. Augustine, St. Austin, St. Augoustinos, Blessed Augustine, or St. Augustine the Blessed, was Bishop of Hippo Regius, the present-day Annaba, Algeria. He was a Latin-speaking philosopher and theologian who lived in the Roman Africa Province. His writings were very influential in the development of Western Christianity. In his early years Augustine was heavily influenced by Manichaeism and afterward by the Neo-Platonism of Plotinus. After his conversion to Christianity and baptism in 387, Augustine developed a new approach to philosophy and theology, accommodating a variety of methods and different perspectives. He believed that the grace of Christ was indispensable to human freedom, and he framed the concepts of original sin and just war.