Battle of Cambrai
The Battle of Cambrai was a British attack in the First World War, followed by the biggest German counter-attack against the British Expeditionary Force since 1914. Wikipedia
Dates: Nov 20, 1917 – Dec 6, 1917
Territorial changes: British capture Havrincourt, Flesquières, Ribécourt-Dreslincourt; Germans capture Gonnelieu