Battle of Alexander Fort
1919 CE.
Shown on the map at 44.517°, 50.267°.
The Battle of Alexander Fort (or Battle of Tyub-Karaganskom), was a naval battle fought in the Caspian Sea during the Russian Civil War at the naval military base of Fort Alexandrovsky.
Text from the Wikipedia article Battle of Alexandrovsky Fort, licensed CC BY-SA 4.0.