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
Action of 25 September 1917 defeat German counter-attacks, by advancing no more than and then consolidating their positions, preferably on reverse-slopes. When the Germans counter-attacked, they would encounter a British defence-in-depth protected by artillery and suffer many casualties to little effect, rather than the small and disorganised groups of infantry that the Germans had driven back on 31 July, After the big defeat at the Battle of the Menin Road Ridge on 20 September, the 4th Army changed the organisation of regiments and battalions in their defensive positions. During August, each German front-line division had kept two regiments in the front position, with all six