The feast of the Annunciation celebrates the angel Gabriel’s announcement to the Virgin Mary that she was to become the mother of the Messiah, and her willing submission to God’s will.
Source: The Annunciation of Our Lord | For All the Saints
The feast of the Annunciation celebrates the angel Gabriel’s announcement to the Virgin Mary that she was to become the mother of the Messiah, and her willing submission to God’s will, whereupon the Word of God was conceived and made incarnate in her womb.
The celebration of the feast probably began in the East in the fifth century and was introduced into the West in the sixth and seventh centuries. By the time of the Tenth Synod of Toledo in 656, it was celebrated nearly universally in the Church. While the feast falls exactly nine months before December 25, it is likely that the dating of the birth of Jesus depends on the dating of his conception, rather than the other way round.
There was widespread belief amongst first century Jews in the “integral age” of prophets and other great men of God, like Abraham; that is, that their lives formed an integral whole, and that they died on the same dates as their birth or conception. Thus, from a presumed dating of the crucifixion to March 25, the angelic announcement to Mary and the conception of Jesus were dated to March 25, and the birth of Jesus to December 25, nine months later.
Gabriel announced to Mary that she would conceive and bear a Son who would be the Messiah, the Son of the Most High, whose name would be Jesus. Astounded, Mary asked how this could be so, since she was a virgin and as yet unmarried. The angel replied that the Holy Spirit would come upon her, and that the power of the Most High would overshadow her, and through this divine means she would conceive. “With God,” said Gabriel, “nothing is impossible.”
This is, therefore, the first feast in the Nativity Cycle, the miraculous conception of Our Lord and Saviour, Jesus Christ, by the Annunciation of the Archangel Gabriel to the Virgin Mary – even though we are still in Lent! It is, to me, fascinating to see how the cycles and seasons of the Christian year overlap and mutually infuse one another, even as do the cycles and seasons of the natural year… concerning which, it is very appropriate that as Christ is “the Sun of Righteousness,” we should celebrate these His feasts at or near the Solstices and Equinoxes!