Mother of God of the Sign, Czestochowa and Damascus
Our Lady of Czestochowa is an icon of St. Luke brought to Constantinople by St. Helena which eventually ended up in Poland with Catholic King Ladislaus. The image was damaged by a Tartar arrow (on the neck) and in 1430 by the Protestant Hussite heretics who cut the icon in three pieces and left two sword slashes on the Virgin's cheek The slashes defied efforts to cover when the icon was repaired.
The icon, called 'black' because of the smudge of oil lamps over the years, is credited with saving 300 Polish Catholic defenders from 12,000 Prostant Swedish invaders in 1655 leading to Catholic King Casimir crowning the icon the 'Queen of Poland'. It later preserved Polish freedom from and Russian communists in 1920.
Many similar icons have protected other Russian cities notably Kursk where it was discovered in the late 13th century by a hunter. The Kursk icon miraculously rejoined itself after being cut in two by a Tartar swordsman and provided protection for the city many times thereafter.