Siege of Soissons
1870 CE.
Shown on the map at 49.381°, 3.322°.
The Siege of Soissons (11 September 1870 – 16 October 1870) was a military engagement during the Franco-Prussian War, ending with the capitulation of Soissons.
Text from the Wikipedia article Siege of Soissons, licensed CC BY-SA 4.0.