Chemical weapons and the United Kingdom army against British and Canadian soldiers near Ypres, Belgium, in 1917 and later also against the French Second Army. The name Yprite comes from its usage by the German army near the town of Ypres. The Allies did not use mustard gas until November 1917 at Cambrai, France, after the armies had captured a stockpile of German mustard-gas shells. It took the British more than a year to develop their own mustard gas weapon, with production of the chemicals centred on Avonmouth Docks. (The only option available to the British was the Despretz–Niemann–Guthrie process). This was used first in September
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