Cyril of Alexandria
c. 376 – 444 · Bishop of Alexandria
Feast: 27 June (Catholic) · 9 June (Orthodox)

Patriarch of Alexandria. Chief architect of Christological orthodoxy; presided over the Council of Ephesus (431) which condemned Nestorius.
Highlights
- Main contribution
- Cyril forced the church to decide whether Christ is one acting Lord or a conjunction of divine and human subjects.
- Event connection
- Council of Ephesus (431)
- Best first read
- On the Unity of Christ
- Primary source
- Cyril, Epistulae (esp. 4, 17, 39)
Cyril forced the church to decide whether Christ is one acting Lord or a conjunction of divine and human subjects. Against Nestorius, he insisted that the one born of Mary is the eternal Word incarnate, which is why Theotokos mattered. The Council of Ephesus in 431 vindicated his central claim, and Chalcedon later had to preserve it while also speaking clearly about Christ's two natures. Cyril's politics could be ugly and his Alexandria was violent, but his Christology became one of the foundations of orthodox faith.
Notable works
- ·On the Unity of Christ · 438
Primary sources
- ·Cyril, Epistulae (esp. 4, 17, 39)
- ·Acta Concilii Ephesini (431)
- ·Socrates Scholasticus, Hist. Eccl. 7

Book of the day
On the Unity of Christ
Cyril of AlexandriaA reading pick tied to today's figure, quote, era, or event. The best short entry into the Nestorian controversy and why 'one Christ' mattered so much.
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