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
Actions of 30 September – 4 October 1917 were to be replaced by a policy of fighting for every piece of ground. Armin thought that even if counter-attacks failed to recapture ground, the British would keep more troops in the front line and that German infantry casualties were no worse in counter-attacks than under British barrages. On 30 September, the 4th Army issued an operation order for more field artillery bombardments between British attacks and that at least half of the heavy artillery ammunition was to be used for observed fire on captured pill-boxes, command posts and machine-gun nests, duckboard tracks and field railways. Gas bombardments were to