We know that this Icon appeared on April 7, 732. Later it was taken from Rome to Russia. In 1709, after the Battle of Poltava, Emperor Peter the Great prayed before it, and offered up words of thanks and praise to the Lord for having given him such a glorious victory over the foe. One should not confuse this Icon with the Tsar’grad [Imperial City] Icon, celebrated on April 25 and September 17, or with the Constantinople Icon, which is celebrated on May 11. The Byzantine Icon is also celebrated on May 1.
Translated from E.Poselyanin