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
British home army in the First World War the New Army over the Territorial Force. Fear of invasion persisted throughout the first months of the war; Kitchener's decision was motivated in part by his concern that the Territorial Force should not be diverted from what he regarded as its primary task of defending the homeland. German success on the continent in September and October opened up the prospect of the French channel ports being used to launch an invasion that could outflank the main British coastal defences north of the Thames. To allow rapid redeployment of the Central Force across the river, construction was begun on a pontoon