the eve of World War II in Italy, as well as Germany, the USSR, Britain, France and Czechoslovakia, decided to upgrade its fleet of heavy guns to retain the status of military power. Project 210 mm howitzers was completed by 1935, but to develop the production tools in factories firm Ansaldo was only a year later. In 1938 howitzer entered service of the Italian Army. Artillery system design contained a number of innovations, such as column book-rests carriage with a powerful base plate, sliding frame with developed openers, lift truck wheel on the balancing suspension stroke. Wheel course allowed to carry a weapon only a short distance and the roads paved. When transporting long-distance howitzer versed in two parts, and its subsequent assembly was taking so long.
Italian industry was not able to establish a mass production of 210-mm guns, it also began production in Hungary, where howitzer repeatedly upgraded and designated respectively 21 cm-39M 21-40M cm and 21 cm-40a. M. Since September 1943 these guns under the name 21-cm howitzers 520 (i) entered service and German troops. Total of 346 units were produced. 210-mm howitzers were used on all fronts of the Second World War and repeatedly became trophies of the Red Army.
After the war, in the process of demilitarization of Italy, all of its heavy weaponry was divided between the countries of the winners. However, unlike ships, howitzers not arouse the interest of the Allies, and all went to be scrapped, despite the little worn-out.