The Fiat-Ansaldo M11/39 medium tank was used from 1940 through the early period of World War II. The M11/39 was developed as a "breakthrough tank" ("Carro di Rottura"). It was replaced by the Fiat-Ansaldo M13/40 medium tank which was used in the Greek campaign and in the North African Campaign. The M13/40 was not used on the Eastern Front; Italian forces there were equipped only with Fiat L6/40s and Semovente 47/32 tank destroyers. Armament was sufficient for 1940–41, but did not keep up with the increased armor and firepower on Allied or German tanks and anti-tank guns; its engine was underpowered and unreliable, a condition worsened by the harsh desert climate and the initial lack of training of their crews. Beginning in 1942, the Italian Army recognized the firepower weakness of the M13/40 series and employed the Semovente 75/18 self-propelled gun alongside the tanks in their armored units, which proved capable of destroying the enemy medium tanks.