The infantry tank was designed to work in concert with infantry in the assault, moving mostly at a walking pace, and carrying heavy armour to survive defensive fire.
In order to give them the required speed, cruiser designs sacrificed armour and armament compared to the infantry tanks.
Historically, the concept of assault guns was very similar to that of the infantry tank, as both were combat vehicles intended to accompany infantry formations into battle.
The infantry tank, according to Guderian, was to be heavily armored to defend against enemy anti-tank guns and artillery.
The Infantry Tank Mark II, best known as the Matilda, was a British infantry tank of the Second World War.
The split between the infantry tank and cruisers had its origins in the World War I division between the first British heavy tanks and the faster Whippet Medium Mark A and its successors the Medium Mark B and Medium Mark C. During the interbellum, British tank experiments generally followed these basic classifications, which were made part of the overall doctrine with the work of Major-General Percy Hobart and the influence of Captain B.H. Liddell Hart.
The operation was decided by the infantry tanks, after the failure of the cruiser tanks of the 7th Armoured Division to overcome the Axis tank forces in the open desert.
By contrast the Infantry tank Matilda II fielded in lesser numbers was largely invulnerable to German gunfire and its gun was able to punch through the German tanks.