Commemoration of the Earthquake of 447

During the reign of Emperor Theodsios II (402-450) the city of Constantinople was shaken by earthquakes for nearly four months. At that time several churches, houses, and the city's stone walls collapsed and were destroyed. All the inhabitants of the city were terrified. Patriarch Proclus (November 20) organized a barefoot Cross Procession and solemnly prayed for God to protect them. While this was taking place, the tremors increased dramatically, and a young boy in the crowd was lifted up into Heaven by some invisible power, and the people, cried out, "Lord, have mercy."

After returning to earth, the boy told the people that he had heard the Angels glorifying God by singing "Holy God, Holy Mighty, Holy Immortal, have mercy on us," and that a voice had commanded him to tell Patriarch Proclus that henceforth the people should supplicate God in this way, without adding anything to it. The Patriarch instructed the people to sing this hymn, whereupon the ground stopped shaking and the child reposed.

From that time the hymn was inserted into the Divine Liturgy, just as it was sung by the people during the earthquake, and as it is still sung up to the present day.