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
Opposing forces in the Polish September Campaign Poland successfully used 10 regular armoured trains against German forces, which were unprepared to face this kind of combat vehicle considered in 1939 so obsolete by German planners to be given any serious consideration. Although the trains proved indeed vulnerable to air attack, losses incurred against Polish trains ("Śmiały" Armored Train destroyed nearly 100 German tanks during the battles around Mokra village) convinced the Germans to reintroduce this type of vehicle into their own army after the September Campaign. Experience in the Polish-Soviet War (1919–1921), the only recent, major conflict the independent Second Polish Republic took part in, shaped Polish