St. Cyril, Archbishop of Alexandria, is one of the most significant theologians of his time, a follower of the traditions of the Alexandrian school, and the creator of the Christological doctrine. He was born into a noble and pious Christian family in 374. In addition to the Holy Scriptures, the saint studied secular sciences, including philosophy. In his youth, Saint Cyril entered the monastery of Saint Macarius in the Nitrian Mountains, where he stayed for six years. Patriarch Theophilus of Alexandria (385-412) ordained him to the rank of deacon, assigned him to the clergy, and, seeing his talent, commissioned him to preach sermons. After the death of Patriarch Theophilus, Saint Cyril was elected to the patriarchal throne of the Church of Alexandria and led the fight against the heresy that had spread in Alexandria, expelling heretics from Alexandria.

St. Cyril ruled the Church of Alexandria for 32 years. In 403, when Saint Cyril was still a deacon and accompanied his uncle, Archbishop Theophilus, to the Council convened against Saint John Chrysostom, Saint Cyril inherited a lifelong prejudice against Chrysostom. One day, in a dream, he saw a wonderful temple in which the Mother of God was located, surrounded by a host of Angels and saints, including St. John Chrysostom, who did not allow St. Cyril to worship Her. The Mother of God asked St. John to forgive St. Cyril: "Forgive him for Me, for he has worked hard for My honor, glorified Me among men, and called Me the Theotokos." St. John replied: "According to Your intercession, Lady, I forgive him," and then lovingly embraced and kissed St. Cyril. Having called together all the Egyptian bishops, St. Cyril celebrated a solemn celebration in honor of St. John Chrysostom.

Saint Cyril died in 444, leaving many works. Especially noteworthy are the Interpretations of the Gospels of Luke, John, and the Epistles of the Apostle Paul to the Corinthians and Hebrews.