Battle of the Lys
1940 CE.
Shown on the map at 51.055°, 3.734°.
The Battle of the Lys (French: Bataille de la Lys, Dutch: Leieslag) was a major battle between Belgian and German forces during the German invasion of Belgium of 1940 and the final major battle fought by Belgian troops before their surrender on 28 May. The battle was the bloodiest of the 18 Days' Campaign. The battle was named after the Leie (French: Lys), the river at which the battlefield occurred.
Text from the Wikipedia article Battle of the Lys (1940), licensed CC BY-SA 4.0.