The Benedictine Office celebrates today as a memorial of St Cyril, but his feast is on February 9 in the 1962 Roman calendar (this year displaced by the Sunday). Here are some readings on him from an older form of that Office:
The praises of Cyril of Alexandria have been celebrated not only by one writer or another, but have even been registered in the acts of the Ecumenical Councils of Ephesus and Chalcedon. He was born of distinguished parents, and was the nephew of Theophilus, Pope of Alexandria. While he was still young he displayed marks of his excellent understanding. After giving a deep study to letters and science he betook himself to John, Bishop of Jerusalem, to be perfected in the Christian faith. After his return to Alexandria, and the death of Theophilus, he was raised to that see. In this office he kept ever before his eyes the type of the Shepherd of souls as it had been laid down by the Apostle; and by ever adhering thereto deservedly earned the glory of an holy Bishop.
Zeal for the salvation of souls was kindled in him, and he undertook all care to keep in the faith and in soundness of life the flock unto him committed, and to preserve them from the poisonous pastures of infidelity and heresy; hence, in accordance with the laws, he caused the followers of Novatus to be expelled from the city, and those Jews to be punished who had been induced by rage to plan a massacre of the Christians. His eminent care for the preservation of the Catholic faith pure and undenied shone forth especially in his controversy against Nestorius, Patriarch of Constantinople, who asserted that Jesus Christ had been born of the Virgin Mary as man only and not as God, and that the Godhead had been bestowed upon Him because of His merits. Cyril first attempted to convert Nestorius, but when he found this hopeless he denounced him to the Supreme Pontiff the holy Celestine.
As delegate of Pope Celestine, Cyril presided at the Council of Ephesus where the Nestorian heresy was condemned; Nestorius deprived of his see; and the Catholic doctrine as to the unity of Person in Christ and the divine Motherhood of the glorious Virgin Mary was laid down amid the rejoicings of all the people, who escorted the bishops to their lodgings with a torch-light procession. For this reason Nestorius and his followers made Cyril the object of slanders, insults, and persecutions which he bore with profound patience, having all his care for the purity of the faith, and taking no heed to what the heretics might say or try against him. At length he died a holy death, in the year of salvation
444 And of his own papacy the 32nd. After vast work for the Church of God, and leaving behind him divers writings directed either against heathens and heretics or to the exposition of the holy Scriptures and of Catholic doctrine, the Supreme Pontiff Leo XIII. extended to the Universal Church the Office and Mass of this most eminent champion of the Catholic faith, and light of the Eastern Church.