Saint Cyril of Alexandria (†444) was the Patriarch of Alexandria at the time when the city was at the height of its influence and power within the Roman Empire who 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. The Roman Catholic Church commemorates him on 27 June, considered to be the day of the saint's death. The Eastern Orthodox and Byzantine Catholic Churches celebrate his feast day on 9 June and also, together with Pope Athanasius I of Alexandria, on 18 January.
Saint Cyril of Jerusalem (†386) was a theologian of the Early Church. About the end of AD 350, he succeeded Maximus as Bishop of Jerusalem, but was exiled on more than one occasion due to the enmity of Acacius of Caesarea, and the policies of various emperors. Cyril left important writings documenting the instruction of catechumens and the order of the Liturgy in his day. He is venerated as a saint within the Roman Catholic Church, the Eastern Orthodox Church, the Oriental Orthodox Church, and the Anglican Communion. In 1883, Cyril was declared a Doctor of the Church by Pope Leo XIII and his feastday is commemorated on 18 March.