Cyril was born in 376 in Alexandria and lived a monastic life. He was ordained a priest and succeeded his uncle as bishop of Alexandria in 412. He battled heresy and took a leading role at the Council of Ephesus in 431, which condemned the teachings of Nestorius. He died in 444 and was declared a Doctor of the Church in 1882. – CTS New Daily Roman Missal 2012, p 2785; Christian Prayer 1990, p 1157
