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
Mines in the Battle of Messines (1917) Second Army (General Sir Herbert Plumer), remarked to the press, "Gentlemen, I don’t know whether we are going to make history tomorrow, but at any rate we shall change geography". The Battle of Messines marked the zenith of mine warfare. On 10 August 1917, the Royal Engineers fired the last British deep mine of the war, at Givenchy-en-Gohelle near Arras. As part of allied operations in the Ypres Salient, British mining against the German-held salient at Wijtschate near Messines had begun in spring 1915, with diggings below the surface. The concept of a deep mining offensive was devised in September