Saint Celestine I remembered on July 27

Saint Celestine I, pope from 422 to 432, is commemorated on July 27. A native of Campania, he succeeded Pope Boniface I and devoted his papacy to defending Catholic doctrine against the heresies of his time.

He opposed Pelagianism, which denied original sin, and Nestorianism, which challenged the divine nature of Christ. In 429 he sent a mission led by Saint Germane of Auxerre to confront Pelagianism in Britain, and in 431 he dispatched Palladius to the Irish‑Scottish churches. Celestine also convened the Council of Ephesus in 431, which formally condemned Nestorian teaching and affirmed the unity of Christ’s nature. His close friendship with Saint Augustine of Hippo and collaboration with Cyril of Alexandria were central to his doctrinal efforts.

The saint’s feast day is observed in various Catholic communities, recalling his role in early church discipline and missionary outreach.