type remained a decisive factor in the early years of the Cold War. The purpose of heavies would not change until their replacement by the main battle tank. Often referred to as MBTs, these designs effectively filled all roles required by armies, thus rendering more specialized designs obsolete. World Wars The first British tank, the Mark I of World War I, was introduced to break through German defensive lines of trenches and barbed wire. When lighter, faster tanks were introduced, the larger tanks were classified as heavy. The Char 2C was one of the largest tanks ever produced. At the start of World War II, France and the Soviet Union were the only countries to have inventories of heavy tanks, such as the Char B1, T-35, and KV-1. The Matilda II was designed under the British infantry tank concept which is similar to the heavy tank having thick armour and tending to weigh more than their other tanks. It’s usually separate because they have less firepower with their cruiser tanks (comparable to mediums) at the time having the same main armament but more machine guns. Later war examples were the German Tiger I and II, as well as the Soviet IS series. Note that "heavy" versus "medium" is more a question of tactical roles than weight; the Panther, for example, was a "medium" tank that outweighed most Allied "heavy" tanks. American forces rarely fielded heavy tanks, as they still held on to the infantry-support doctrine like the British; in addition, the Americans recognized the logistical and mobility issues that came with possessing a heavy tank force and did not want to compromise its 3,000 mile supply line to Europe. The M6 heavy tank was designed in 1940 but held few advantages over medium tanks and planned production of several thousand was stopped. The Anglo-American T14 Heavy Tank project started in 1941 did not deliver a pilot model until 1944. The US preferred to use tank destroyers (mobile but relatively lightly armoured vehicles) for anti-tank defence, and prior to 1944 there were few indications that the M4 Sherman was outclassed in terms of armor and weapons by German heavy tanks which were few in number. Near the end of World War II, a few early model M26 Pershing were sent to Europe to gain combat experience. Aside from these the closest the Americans came to putting a heavy tank into service