Chemical weapons in World War I in Palestine during the Second Battle of Gaza. Russia began manufacturing chlorine gas in 1916, with phosgene being produced later in the year. Most of the manufactured gas was never used. The British Army first used mustard gas in November 1917 at Cambrai, after their armies had captured a stockpile of German mustard gas shells. It took the British more than a year to develop their own mustard gas weapon, with production of the chemicals centred on Avonmouth Docks. (The only option available to the British was the Despretz–Niemann–Guthrie process). This was used first in September 1918 during the breaking
Actions of 30 September – 4 October 1917 diary note that it had been an awful experience; he did not know what to do against the British. Erich Ludendorff the (Quartermaster-General of the German Army, equivalent to the British Chief of the General Staff) conferred on 29 September with (field marshal) Crown Prince Rupprecht the commander and (lieutenant-general) Hermann von Kuhl the chief of staff, of "Heeresgruppe Kronprinz Rupprecht von Bayern" (Army Group Rupprecht of Bavaria), the 4th Army commander, General Sixt von Armin and the 4th Army chief of staff, (major-general) Fritz von Loßberg. The staff officers of the 4th Army (corps headquarters) agreed that defensive manoeuvres