St. Celestine I
Celestine · 422 – 432
Sent St. Patrick to Ireland and supported the Council of Ephesus against Nestorianism.
Celestine I was pope from 422 to 432, a decade that saw major developments in doctrine and mission. He commissioned Palladius and supported Patrick's mission to Ireland. He also backed Cyril of Alexandria against Nestorius, who taught that Mary should not be called Theotokos (Mother of God). The Council of Ephesus in 431 vindicated Celestine's position, affirming that Mary truly bore God in the flesh.
Why He Matters
Celestine I connected two of the most consequential events in fifth-century Christianity: the evangelization of Ireland and the defense of Mary's title as Mother of God. Both decisions still shape Catholic life across the world.