Siege of Belaya
1634 CE.
Shown on the map at 55.833°, 32.933°.
The siege of Belaya was the final military episode of the Smolensk War. The defense of the fortress by its small Russia garrison against a large Polish-Lithuanian army of King Władysław IV Vasa thwarted the king's plan to march against Moscow and made him sign the Treaty of Polyanovka in which he relinquished his claims to the Russian throne.
Text from the Wikipedia article Siege of Belaya, licensed CC BY-SA 4.0.