Battle of Saarbrücken
1870 CE.
Shown on the map at 49.233°, 7.000°.
The Battle of Saarbrücken was the first major engagement between the French Empire and the Kingdom of Prussia during the Franco-Prussian War. The battle took place on 2 August 1870, around the city of Saarbrücken.
Text from the Wikipedia article Battle of Saarbrücken, licensed CC BY-SA 4.0.