St. Cyril of Alexandria was a 5th-century Church Father and theologian, best known for his defense of the Virgin Mary as Theotokos (Mother of God) against the Nestorian heresy. As Patriarch of Alexandria, he fought to preserve the unity of the Church and played a key role in the Council of Ephesus (431 AD). He is venerated as a Doctor of the Church and one of the greatest defenders of Christ's divinity.
St. Cyril was born around 376 AD in Alexandria, Egypt, into a Christian family. He received an excellent education in theology, philosophy, and rhetoric. His uncle, Theophilus, the Patriarch of Alexandria, guided his early religious formation and eventually appointed him as his successor in 412 AD.
As Patriarch, Cyril worked tirelessly to defend orthodox Christian teachings. His greatest theological challenge came from Nestorius, the Patriarch of Constantinople, who claimed that Mary should be called "Christotokos" (Christ-bearer) instead of "Theotokos" (God-bearer). Cyril saw this as a denial of Christ’s divine nature and strongly opposed Nestorius.
In 431 AD, Cyril led the Council of Ephesus, where Nestorius’ teachings were condemned, and the title "Mother of God" (Theotokos) for Mary was affirmed. This council had a lasting impact on Christian theology and solidified Cyril's reputation as a defender of the faith.
Aside from his theological works, Cyril also worked to strengthen the Church in Alexandria. His leadership was marked by conflict with heretics and political struggles, but his commitment to the truth never wavered. He wrote extensively, leaving behind important theological texts that continue to influence Christian doctrine.
Cyril died on June 27, 444 AD, after serving as Patriarch for 32 years. He was later declared a Doctor of the Church for his profound contributions to Christology. His writings remain a cornerstone of Catholic and Orthodox theology, and his defense of Mary's divine maternity is celebrated to this day.