The Orthodox Church honors today the church feast of Pokrov Bogorodichen. The feast is both named The Protection of the Theotokos, or The Intercession of the Theotokos as in most Slavic languages, the word "Pokrov" means both "covering" and "protection". 

The feast originated to honor the apparition of the Mother of God in Constantinople in the first half of the tenth century. In the church of  Blachernae, near the city gates during a night vigil, St. Andrew and several others saw the Virgin Mary accompanied by St. John the Baptist, St. John the Theologian and other apostles and angels. She walked to the center of the temple, knelt down and remained in prayer for a long time with her face wet with tears. Then she took off her veil (pokrov) and spread it over the people as a sign of protection. At that time, in 910, the inhabitants of the city were threatened by a barbarian invasion, but after the apparition of the Virgin Mary the danger passed and the city was saved from bloodshed and suffering. 

In gratitude for the protection of the Mother of God, the Church designated this day as an important Christian feast. It is celebrated only in Slavic countries - probably because St. Andrew, who received a vision of the sanctity of this apparition, was a Slav by origin. 

Many Orthodox churches and monasteries in Bulgaria bear the name of The Protection of the Theotokos.