He was born in Alexandria Egypt in 296. He accompanied Bishop Alexander to the Council of Nicaea, and succeeded him as bishop of Alexandria for some 46 years. He fought courageously against the Arian heresy. For this he suffered many hardships and was exiled for 17 years. His writings are outstanding in their explanation and defense of the true teachings of the faith. St John Henry Newman later wrote that he was “a principal instrument after the Apostles by which the sacred truths of Christianity have been conveyed and secured to the world.” He died in 373. CTS New Daily Roman Missal 2012, p 2667-68; Christian Prayer 1990, p 1126.