This doctor of the church, famous for his understanding of and writing about the Incarnation, became bishop of his hometown, Alexandria, Egypt, when he was in his early 30s.
As metropolitan patriarch for 45 years, he fought the heresy of Arius, a well-educated Alexandrian priest; ran afoul of three emperors and was exiled multiple times; and defended church unity despite longstanding difficulties with other bishops.
He improved spirituality in his diocese, increased vocations, preached and wrote many letters, as well as a life of Antony of Egypt, a classic about ascetic and monastic life.
Venerated from the time of his death in both East and West, he is the patron saint of hagiographers.
Text: Catholic News Service