Athanasius of Alexandria

Athanasius of Alexandria (c. 296-373) was the formidable bishop and theologian who became the foremost champion of Nicene orthodoxy against Arianism in the fourth-century church. First as a deacon attending the Council of Nicaea (325) and then as patriarch of Alexandria from 328, he insisted on the full divinity of Christ as consubstantial (homoousios) with the Father, a stance that earned him five exiles under successive emperors and the epithet Athanasius contra mundum ('Athanasius against the world'). His writings, including On the Incarnation, the Life of Antony that helped launch the monastic movement, and his annual Festal Letters, shaped Christian doctrine for centuries; his 39th Festal Letter of 367 is the earliest surviving list of the New Testament canon exactly as it stands today. He is venerated as a Doctor of the Church and a saint across the Catholic, Orthodox, and Coptic traditions.