Our knowledge of St. Cyril’s childhood education and early upbringing is quite meager. According to St. Isidore of Pelusium and church historian Socrates, St. Cyril was born in Alexandria around the year 380. However, others rely on to the chronicles of John, Bishop of Nikiu in seventh century, who states that St. Cyril’s mother and her brother hailed from Memphis, and that St. Cyril was born in the town of Theodosion, Lower Egypt, very close to the current city Mahhalla el Kobra in the region of Mansoura. Recent studies date St. Cyril’s birth to 378 AD, however exact date remains uncertain.
He is known to have had one sister, Isidora, and several nephews. His nephew’s libellus says he had three sisters. When Theophilus, the brother of St. Cyril’s mother, became patriarch of Alexandria in 385, they moved to Mansoura. Soon, she died at a young age from a surgical operation.
Cyril’s education was thorough and comprehensive. At a young age, he studied Greek and Latin. He was later trained in ρητορική, γραμματική, and biblical studies by the time he reached the Catechetical School of Alexandria. Against Julian demonstrates his familiarity with the classic works of Aristotle, Homer, Pythagoreas, Hermes, Euripides, which he probably studied in the Catechetical School. His knowledge of Latin allowed him to access St. Jerome’s commentaries on the Holy Scripture and facilitated his later contacts with Rome.
He then spent five years in the desert of Nitria, studying the Holy Scriptures under St. Macarius, St. Serapion of Thmuis, and St. Isidore of Pelusium. Evieux argues that St. Cyril probably met Evagrius during this stay in the desert. Some have assumed that St. Cyril was a monk under St. Isidore, although very little evidence exists in support of this.
After finishing his studies he probably became a disciple of his uncle, Patriarch Theophilus, as testified by St. Jerome to Rufinus. He stayed in the patriarch’s cell, where he continued his study of the Fathers and won the heart of his uncle. His uncle was certainly present at the Council of Constantinople in 381, during which St. Cyril was a mere lad. It is uncertain whether at this time the Διδασκαλει̃ον was still open, since it began to languish after the departure of St. Didymus.
In 403, Theophilus ordained him a reader in the Church of Alexandria and he began his formal ministry. He accompanied Theophilus to the Synod of the Oak in 408, during which St. John Chrysostom was deposed. On October 17, 412, he was called to be the 24th Patriarch of Alexandria, two days after his uncle’s departure. Upon taking charge of the great see, he faced an onslaught of obstacles: dissenting Jews, unpleased Novatians, and remnants of paganism in Alexandria. As with St. Athanasius and Arianism, St. Cyril’s papacy would then focus on the growing Christological controversy of the day, Nestorianism.