Battle of Riga
1215 CE.
Shown on the map at 57.050°, 24.050°.
The Battle of Riga was an attempt by native Estonian forces to repel the Crusader knights (known as the Livonian Brothers of the Sword) and their allies during the Livonian Crusade.
Text from the Wikipedia article Battle of Riga (1215), licensed CC BY-SA 4.0.