Third Battle of the Aisne
1918 CE.
Shown on the map at 49.383°, 3.733°.
The Third Battle of the Aisne (French: 3e Bataille de l'Aisne) was part of the German spring offensive during World War I that focused on capturing the Chemin des Dames Ridge before the American Expeditionary Forces arrived completely in France. It was one of a series of offensives, known as the Kaiserschlacht, launched by the Germans in the spring and summer of 1918.
Text from the Wikipedia article Third Battle of the Aisne, licensed CC BY-SA 4.0.