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 Theses Actions of 30 September – 4 October 1917 The Actions of 30 September – 4 October 1917 were German methodical counter-attacks ("Gegenangriffe") during the Third Battle of Ypres in Flanders, during the First World War. Hasty counter-attacks () by the German 4th Army during the Battle of the Menin Road Ridge on 20 September and the Battle of Polygon Wood on 26 September, had been costly failures. On 29 September, a review was held at Roulers by Erich Ludendorff the (Quartermaster-General of the German Army, equivalent to the British Chief of the General Staff) with the commanders of "Heeresgruppe