British war crimes September 1915 and continued their usage for the remainder of the war. This was done in retaliation for the use of chlorine by Imperial German Army the preceding April. Following the Imperial German Army's use of poison gas at Ypres, the commander of II Corps, Lieutenant General Sir Charles Ferguson, had said of poison gas: Mustard gas was first used effectively in World War I by the German army against British and Canadian soldiers near Ypres, Belgium, in 1917 and later also against the French Second Army. The name "Yperite" comes from its usage by the German army near the
Actions of 30 September – 4 October 1917 were to be replaced by a policy of fighting for every piece of ground. Armin thought that even if counter-attacks failed to recapture ground, the British would keep more troops in the front line and that German infantry casualties were no worse in counter-attacks than under British barrages. On 30 September, the 4th Army issued an operation order for more field artillery bombardments between British attacks and that at least half of the heavy artillery ammunition was to be used for observed fire on captured pill-boxes, command posts and machine-gun nests, duckboard tracks and field railways. Gas bombardments were to