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
Halberstadt CL.II Halberstadt CL.II The Halberstadt CL.II was a German two-seat escort fighter/ground attack aircraft of World War I. It served in large numbers with the German "Luftstreitkräfte" (Imperial German Army Air Service) in 1917-18. Early in 1917, "Idflieg", the German Army Inspectorate of Flying Troops, developed a requirement for a new type of two-seat aircraft, smaller than the existing C-type aircraft. This type, to be known as CL-type (Light C type) aircraft, were to be used to equip "Schutzstaffeln" (Protection flights) to escort reconnaissance aircraft. To meet this requirement, Halberstadt developed an aircraft based on its earlier, unsuccessful Halberstadt D.IV single-seat