St. Athanasius, also called Saint Athanasius of Alexandria or Saint Athanasius the Apostolic, (born c. 293, Alexandria—died May 2, 373, Alexandria; feast day May 2), theologian, ecclesiastical statesman, and Egyptian national leader. He was the chief defender of Christian orthodoxy in the 4th-century battle against Arianism, the heresy that the Son of God was a creature of like, but not of the same, substance as God the Father. His important works include The Life of St. Antony, On the Incarnation, and Four Orations Against the Arians.