Our Lady of Kazan
Our Lady of Kazan was a highly-venerated icon of the Russian Orthodox Church. It is said to have originated in Constantinople and was transported to Russia where it disappeared, only to be miraculously rediscovered in Kazan after a vision in 1579. Prayers to this icon were credited for saving the country from invasion by Poles, Swedes and Napoleon.
In 1904 the icon was stolen and, though its gold frame was recovered, the icon itself was never seen again. The disasters of the 1905 Russian Revolution, the Great War and the Communist takeover are attributed to its loss.