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
German Army (German Empire) German Army (German Empire) The Imperial German Army () was the name given to the combined land and air forces of the German Empire (excluding the ' maritime aviation formations of the Imperial German Navy). The term ' is also used for the modern German Army, the land component of the ". The German Army was formed after the unification of Germany under Prussian leadership in 1871 and dissolved in 1919, after the defeat of the German Empire in World War I. The states that made up the German Empire contributed their armies; within the German Confederation, formed after the