The Feast of the Annunciation, contemporarily the Solemnity of the Annunciation, commemorates the visit of the archangel Gabriel to the Virgin Mary, during which he informed her that she would be the mother of Jesus Christ, the Son of God.
It is celebrated on 25 March each year.
It is a principal Marian feast, classified as a solemnity in the Catholic Church.
Two examples in Catholicism of the importance attached to the Annunciation are the Angelus prayer, and the event's position as the first Joyful Mystery of the Rosary.
The Feast of the Annunciation was celebrated as early as the fourth or fifth century.
The first certain mentions of the feast are in a canon, of the Council of Toledo in 656, where it was described as celebrated throughout the Church, and in another of the Council of Constantinople "in Trullo" in 692, which forbade the celebration of any festivals during Lent, excepting the Lord's Day (Sunday) and the Feast of the Annunciation.
As this feast celebrates the Incarnation of the Second Person of the Trinity, many Church Fathers, including St. Athanasius, St. Gregory of Nyssa, and St. Augustine, have expounded on it.
When the calendar system of Anno Domini was first introduced by Dionysius Exiguus in AD 525, he assigned the beginning of the new year to 25 March, because according to Catholic doctrine, the age of grace began with the Incarnation of Christ at the Annunciation, on which date Jesus Christ is believed to have been conceived in the Virgin Mary by the Holy Spirit.
