Cyril was born in Alexandria, Egypt, and was the nephew of its patriarch, Theophilus. Classically educated, he was ordained by his uncle, whom he succeeded as patriarch in 412. He had helped Theophilus discredit and depose St. John Chrysostom from Constantinople, in what may have been a rivalry between the two ancient sees. As patriarch, he exercised his authority hastily and violently, drawing severe criticism, and was embroiled in heretical controversies, chiefly against Nestorius of Constantinople, who taught that Mary was not the mother of God. Cyril’s orthodoxy eventually was upheld by pope and emperor. This most brilliant theologian of the Alexandrian tradition was declared a doctor of the church in 1882; he is the patron of Alexandria.