St. Cyril of Alexandria (376 - 444)

Was the Patriarch of Alexandria from 412 to 444. He was enthroned when the city was at the height of its influence and power within the Roman Empire. Cyril wrote extensively and was a leading protagonist in the Christological controversies of the late-4th and 5th centuries. He was a central figure in the Council of Ephesus in 431, which led to the deposition of Nestorius as Patriarch of Constantinople.

Cyril is counted among the Church Fathers and the Doctors of the Church, and his reputation within the Christian world has resulted in his titles Pillar of Faith and Seal of all the Fathers. Cyril regarded the embodiment of God in the person of Jesus Christ to be so mystically powerful that it spread out from the body of the God-man into the rest of the race, to reconstitute human nature into a graced and deified condition of the saints, one that promised immortality and transfiguration to believers. Nestorius, on the other hand, saw the incarnation as primarily a moral and ethical example to the faithful, to follow in the footsteps of Jesus. Cyril's constant stress was on the simple idea that it was God who walked the streets of Nazareth (hence Mary was Theotokos, meaning "God bearer", which became in Latin "Mater Dei or Dei Genetrix", or Mother of God), and God who had appeared in a transfigured humanity. Nestorius spoke of the distinct "Jesus the man" and "the divine Logos" in ways that Cyril thought were too dichotomous, widening the ontological gap between man and God in a way that some of his contemporaries believed would annihilate the person of Christ.