British war crimes September 1915 and continued their usage for the remainder of the war. This was done in retaliation for the use of chlorine by Imperial German Army the preceding April. Following the Imperial German Army's use of poison gas at Ypres, the commander of II Corps, Lieutenant General Sir Charles Ferguson, had said of poison gas: Mustard gas was first used effectively in World War I by the German army against British and Canadian soldiers near Ypres, Belgium, in 1917 and later also against the French Second Army. The name "Yperite" comes from its usage by the German army near the
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