This icon appeared as unidentified on a Russian forum site (cirota.ru).
It is a very uncommon type, yet in spite of the seemingly garbled inscription at the top, it is clear that what it represents is a story found in the traditions associated with the garments of Mary.
You may recall an older posting here on supposed “garment” relics, among them the robe of Mary:
In that posting, there was brief mention of a tradition that the robe of Mary is said to have saved the city of Constantinople from invasion in the year 860. Well that is the event depicted here.
The tradition from Greek chronicles and from the Russian Tale of Bygone Years (Повесть временных лет/Povyest’vremennuikh lyet) relates that on June 18, 860, a fleet of “Rus'” ships under Prince Askold was raiding in the Black Sea and even as far as the Bosphorus, and came to Constantinople intent on plunder and siege.
Patriarch Photios of Constantinople then took the robe of Mary from the shrine where it was kept, and going in procession outside the walls of the city, he came to the shore beyond which lay the invading fleet. He dipped the robe in the water, and a great storm miraculously arose that raised great waves that began to dash the ships on the rocks, breaking them apart and sinking them. Discouraged by this disaster, the Rus’ invaders gave up their siege and departed with their remaining ships.
If we look at the image, we see Photios standing on the shore in his clerical garments at left, holding the robe of Mary in his hands. And to the right, we see the helmeted and armored warriors in the Rus’ ships of Askold on the waves of the sea:
Here is a more detailed Russian fresco image from 1648 of the same event: