Battle of Doiran
1917 CE.
Shown on the map at 41.188°, 22.721°.
The Battle of Doiran was a 1917 battle between the United Kingdom and Bulgaria during World War I. The battle ended in decisive Bulgarian victory, leading to 16 months of silence on the front before the Third Battle of Doiran.
Text from the Wikipedia article Battle of Doiran (1917), licensed CC BY-SA 4.0.