The feast day celebrates the appearance of the Theotokos, Mother of God at Vlachernae in the 10th Century. At the end of Saint Andrew of Constantinople, he, with his disciple Saint Epiphanius, and a group of the faithful, saw the Mother of God, Saint John the Baptist, and several other Saints and Angels during a vigil in the Church of Vlachernae, nearby the city gates. The Vlachernae Palace church was where several of her holy relics were kept. The holy relics were her robe, veil, and part of her belt that had been transferred from Palestine during the 5th century.

The holy great-martyr Demetrios was born in the city of Thessaloniki and was the son of noble and pious parents. His father was the Military Governor of Thessaloniki, and secretly believed in our Lord Jesus Christ and labored for Him. He did not dare, however, to confess the Lord's Most Holy Name openly, for at that time the impious emperors were tormentors of Christians and had raised up a great persecution against the faithful (believers). Since he feared the threats of the cruel and iniquitous rulers, he hid within himself the pearl of great price, the faith which is in Christ. But in his palace he secretly kept two holy icons, adorned with gold and precious stones, one of our Incarnate Savior Jesus Christ and the other of the Most Holy Theotokos.

Saint Luke the Evangelist mentions in the book of Acts of the Apostles: "She was devoted to good works and acts of charity" (9:36). She lived in the Palestinian town of Joppa, where she was a weaver by trade. She'd become a Christian and lived out her faith in her everyday life. Her heart over flowed with innocent love for those of her fellow-citizens who were in pain or poverty. For this reason she worked day and night making clothing which she then sold, giving the proceeds to those in need.