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
German Type UC III submarine German Type UC III submarine Type UC III minelaying submarines were used by the Imperial German Navy () during World War I. They displaced at the surface and submerged, carried guns, 7 torpedoes and up to 14 mines. The ships were double-hulled with improved range and sea-keeping compared to the UC II type. The type had better seagoing, maneuvering and turning capabilities than its predecessor, while underwater stability was reduced. A total of 113 Type UC III submarines were ordered by the Imperial German Navy, but only 25 U-boats were completed before the Armistice with Germany in 1918. Of those,