The Italian army was mainly equipped with tankettes of the L3 series in the 1930s, and these, armed with machine guns, formed the main armor strength of Italy as late as 1940. Italy began fielding heavier tanks beginning with the Fiat M11/39 with a 37 mm main gun in 1940. This tank and its derivatives, the M13/40, M14/41 and the M15/42 (all with 47 mm main guns) were closely comparable in combat power to light tanks such as the Soviet T-26. A heavier design, the P40 with a 75 mm main gun, was designed, but saw no service with Italian forces as it became ready at the time of the Armistice of Cassibile with the Allies, after which the Germans took over production, and used roughly one hundred of them. Another tank design, the Fiat M16/43, was developed to match the British cruiser tanks but work on it was stopped when the Axis was pushed out of North Africa in May 1943.