Ypres east of the town. The first gas attack occurred against Canadian, British, and French soldiers, including both metropolitan French soldiers as well as Senegalese and Algerian tirailleurs (light infantry) from French Africa. The gas used was chlorine. Mustard gas, also called Yperite from the name of this town, was also used for the first time near Ypres, in the autumn of 1917. Of the battles, the largest, best-known, and most costly in human suffering was the Third Battle of Ypres (31 July to 6 November 1917, also known as the Battle of Passchendaele), in which the British, Canadian, ANZAC, and
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