The title Mother of God has its roots in the early centuries of Christianity, dating back to the third or fourth century. The Greek expression Theotokos, meaning “God bearer,” was formally affirmed as Catholic teaching at the Council of Ephesus in 431. With this declaration, it became the Church’s first Marian dogma. At the conclusion of the council, large crowds filled the streets in celebration, proclaiming praise to the Theotokos.

This belief is firmly grounded in the doctrine of the Incarnation, as reflected in the words of Saint Paul: “God sent his Son, born of a woman, born under the law” (Galatians 4:4).

The Second Vatican Council also highlights Mary’s unique role in the life of the Church. In its Dogmatic Constitution Lumen Gentium or Light of the People, the title Mother of God is used twelve times when describing Mary’s mission and significance.

The same day is also observed by the Catholic Church as the World Day of Peace, a global observance introduced by Pope Paul VI and later reaffirmed by Pope John Paul II.