Sulfur mustard later also against the French Second Army. The name Yperite comes from its usage by the German army near the town of Ypres. The Allies did not use mustard agent until November 1917 at Cambrai, France, after the armies had captured a stockpile of German mustard shells. It took the British more than a year to develop their own mustard agent 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 1918 during the breaking of the Hindenburg Line. Mustard agent was dispersed
6th Army (German Empire) eventually come to be regarded as one of Germany's most able generals. On 24 September 1915 the 6th Army was the target for the British Army's first chlorine gas attack of the war. Despite the horrific casualties inflicted, the British offensive became bogged down after several days. Rupprecht was promoted to the rank of field marshal ("Generalfeldmarschall") in July 1916 and assumed command of Army Group Rupprecht on 28 August that year, consisting of the 1st, 2nd, 6th and 7th Armies. Following Rupprecht's promotion, command of the 6th Army was given to General Ludwig von Falkenhausen. In March 1917 the