Solemnity of Mary, Mother of God

The Solemnity of Mary, the Holy Mother of God, is celebrated on the octave day of Christmas, eight days after the birth of the Lord, and honors the Blessed Virgin Mary under her most exalted title. In calling Mary the Mother of God — Theotokos, the God-bearer — the Church confesses that the child she conceived and bore is not merely a man later joined to God, but the eternal Son of God made flesh; her divine motherhood is thus a profession of faith in the mystery of the Incarnation itself.

This truth, defended by St. Cyril of Alexandria and solemnly proclaimed by the Council of Ephesus in the year 431, is the oldest and greatest of Mary's honors, and the feast of the Mother of God is among the most ancient of the Marian celebrations of Rome. Kept on 1 January, the day is also observed by the Church as the World Day of Peace, and it stands as a holy day of obligation, opening the new year under the protection of the Mother of the Redeemer.