Saturday after the third Sunday after Trinity

Cyril was born around 376 in Alexandria, Egypt, into a powerful ecclesiastical family — his uncle, Theophilus, was the formidable Bishop of Alexandria. Cyril was educated thoroughly in classical rhetoric and biblical exegesis and became a deacon under his uncle. When Theophilus died in 412, Cyril was elected to succeed him as Bishop of Alexandria — a see that was among the most powerful in the Christian world.

Cyril inherited a church deeply involved in ecclesiastical politics. Alexandria had long been at odds with the see of Antioch over theological and political issues. Cyril also faced conflicts with the Christian ascetics of Egypt (the desert monks), Jewish communities in Alexandria, and various heretical groups. Cyril's style was uncompromising: he deposed bishops, burned synagogues, and used both intellectual argument and political pressure to enforce his understanding of orthodoxy.

Cyril's greatest theological work involved the Christological controversies. During the 420s and 430s, the Patriarch of Constantinople named Nestorius began teaching what he understood as a careful distinction between the divine and human natures of Christ, insisting that Mary should be called Christotokos ('Christ-bearer') rather than Theotokos ('God-bearer'). Cyril objected strenuously, arguing that Nestorius's language divided the person of Christ and robbed Mary of her rightful title as the bearer of God incarnate.

Cyril convened a council of Egyptian bishops, issued twelve anathemas against Nestorius, and lobbied the imperial court and the Pope in Rome. At the Council of Ephesus in 431, Cyril presided and engineered the condemnation of Nestorius, using political leverage and procedural maneuvers that his opponents condemned as manipulative. Nestorius was deposed and exiled.

Cyril's victory was not unambiguous. His methods at Ephesus alienated many bishops, and the theological settlement proved unstable. Cyril had to make some compromises with the Antiochene party, agreeing to a formula that acknowledged both the unity of Christ's person and the integrity of his two natures — a formulation that would be further refined at the Council of Chalcedon in 451, after his death.

Cyril's legacy carries a shadow in the death of Hypatia, a pagan Neoplatonist philosopher who was murdered by a Christian mob in Alexandria in 415. Some sources suggest Cyril's earlier anti-pagan polemic contributed to the violence; others defend Cyril by noting that the sources are ambiguous and that he was not personally responsible. The historical facts remain disputed.

Cyril died on June 27, 444, having served as Bishop of Alexandria for 32 years. He was immediately recognized as one of the greatest theologians of his age, though his harsh methods and theological rigidity were already controversial.

Traditionally, Cyril was understood as the defender of true Christology and Mariology against heresy. His victory at Ephesus was celebrated as a triumph of orthodoxy. However, even in early sources, his methods were questioned. Contemporaries criticized his use of political pressure and procedural manipulation. The charge of involvement in Hypatia's death has haunted his reputation since antiquity. Some modern scholars defend Cyril by noting the ambiguity of the sources; others argue that his anti-pagan polemic contributed to the culture of violence that resulted in her murder. The tradition is appropriately conflicted about Cyril: celebrating his doctrinal achievement while acknowledging his harsh methods.