Loos, Battle of

In World War I, unsuccessful French-British offensive September 1915 to recover the mining district around the towns of Loos and Lens from the Germans. This was the first action in which the British used gas, but the wind shifted and blew the gas back over British lines.

The German positions were well-fortified, and the British forces were largely composed of fresh volunteers from the Kitchener armies. The attack managed to drive a salient some way into the German lines, but the reserves were badly organized and before they could be brought up a German counterattack drove the British back to their start line, although a second attack further south gained about 3 km/2 mi. Some 500,000 Allied troops were deployed in the battle and the British lost 60,000 casualties including three generals. French casualties are not known precisely but are believed to have been even higher.