Chemical weapons in World War I volatile oily liquid. It was introduced as a vesicant by Germany in July 1917 prior to the Third Battle of Ypres. The Germans marked their shells yellow for mustard gas and green for chlorine and phosgene; hence they called the new gas "Yellow Cross". It was known to the British as "HS" ("Hun Stuff"), and the French called it "Yperite" (named after Ypres). Mustard gas is not an effective killing agent (though in high enough doses it is fatal) but can be used to harass and disable the enemy and pollute the battlefield. Delivered in artillery shells, mustard gas was
3rd Army (German Empire) May 1917. Einem's right wing units would also participate in Erich Ludendorff's Champagne-Marne offensive on 15–17 July 1918 supporting the east flank of the German 1st Army. After suffering severe casualties in battle with John J. Pershing's Allied Expeditionary Force from 26 September – 11 November in the Meuse-Argonne offensive, the army was forced to retreat northward shortly before the war's end. At the end of the war it was serving as part of "Heeresgruppe Deutscher Kronprinz". By the end of the war, the 3rd Army was organised as: The 3rd Army had the following commanders during its existence: 3rd