Athanasius of Alexandria was a prominent 4th-century theologian and the 20th Patriarch of Alexandria. Born around 296, he played a pivotal role in defending Nicene Christianity against Arianism, a movement that challenged the central doctrines of the faith. Serving as patriarch for forty-five years between 328 and 373, his career was marked by intense theological disputes and political struggles. Due to his opposition to Arian leaders and several Roman emperors, he endured five separate periods of exile. He remains a central figure in the history of the early Church and the development of Christian dogma.