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
Memorial Museum Passchendaele 1917 Day 2004. In 2007, during the commemoration of 90 years of the 'Third Battle of Ypres', the MMP1917 organised six thematic exhibitions who took place on different locations. There are also three trails created. In 2013 the restoration of the former vicarage is completed to be used as 'Kenniscentrum'. The main theme of the museum is the Third Battle of Ypres, also known as the Battle of Passchendaele. This was a major battle in 1917 during the First World War which was fought out by the British, Anzac and Canadian troops and the German army. The total loss of human