This festival, one of the Twelve Great Feasts, was instituted in memory of the archangel Gabriel bringing the Holy Virgin the good news that she would give birth to Jesus Christ - the Son of God and the Saviour of the World.
On the day of the festival, Patriarch of Moscow and All Russia Alexis II will conduct a divine liturgy in the Annunciation Cathedral of the Moscow Kremlin - the former private chapel of Russian tsars. A service is held in that temple once a year - on April 7.
Then, in the Kremlin's Cathedral Square, according to an old Russian tradition, students of Orthodox gymnasiums and Sunday parish schools of Moscow will release a flock of pigeons.
The birds are usually furnished by the All-Russian Society for Pigeon-Breeding. But many children bring their own pets to the square in order to give them freedom on the Day of the Annunciation.
According to clergymen, this custom symbolizes a desire of the human soul to get rid of the bonds of sin and reunite with the heaven.
The Annunciation Festival opens a series of events described in the New Testament - the incarnation, earthly life, crucifixion and radiant resurrection of Christ.
The spiritual content of the festival lies in revealing the great mystery of the miraculous incarnation of God's Son from the Holy Virgin, prophesied in the Old Testament in the 8th century BC by the Prophet Isaiah.