Christ the Redeemer (1410s) by Andrei Rublev - Public Domain Byzantine Icon

Christ the Redeemer is an icon discovered by accident in a dilapidated woodshed near Zvenigorod in 1919. With several other icons stored nearby, it was attributed as the work of the great Andrei Rublev, painted for one of Zvenigorod cathedrals in the 1420s. It is exhibited in the Tretyakov Gallery of Moscow. Source

Andrei Rublev was a Russian icon painter born in the 1360s, and died between 1427 and 1430 in Moscow. He is considered to be one of the greatest medieval Russian painters of Orthodox Christian icons and frescos. Source