"The Battle of Cambrai, November-december 1917" German gun captured by the 51st Division at Flesquieres, 24 November 1917. Comment: This is a "21 cm Turmhaubitze M 1891" as it was made by Krupp for the belgian forts Liege, Namur and Antwerp, converted to field guns by the Imperial German Army after they had captured the forts.