Because infantry tanks did not need to be fast, they could carry heavy armour.
One of the best-known infantry tanks was the Matilda II of World War II. Other examples include the French R-35, the British Valentine, and the British Churchill.
During World War II, British cruiser tanks were designed to complement infantry tanks, exploiting gains made by the latter to attack and disrupt the enemy rear areas.
In order to give them the required speed, cruiser designs sacrificed armour and armament compared to the infantry tanks.
The British maintained cruiser tanks, focused on speed, and infantry tanks that traded speed for more armour.
Assault guns are armored fighting vehicles that could combine the roles of infantry tanks and tank destroyers.
In the Second World War, a tank brigade comprised three tank regiments and was equipped with infantry tanks for supporting the infantry divisions.
On 26 January 1931, I. Khalepsky, Head of the Department of Mechanisation and Motorisation of the RKKA, wrote a letter to S. Ginzburg with information obtained via the intelligence service that the Polish government had decided to purchase Vickers 6-Ton light infantry tanks as well as Christie M1931 cavalry tanks and to mass-produce them with the assistance of both the British and French.
At that time, the RKKA had only several dozen outdated Mark V heavy tanks and Medium Mk.A and Renault FT tanks, captured during the Russian Civil War, together with various armoured cars and obsolescent domestic MS-1 (T-18) light infantry tanks.
The successor of the BT tanks was the famous T-34 medium tank, introduced in 1940, which would replace all of the Soviet fast tanks, infantry tanks, and medium tanks in service.
The light one was called the A-20. The more heavily armed and armoured BT derivative, the A-32, was a "universal tank" to replace all the T-26 infantry tanks, BT cavalry tanks and T-28 medium tanks.
The BT-7's successor was the famous T-34 medium tank, introduced in 1940, which replaced all of the Soviet fast tanks, infantry tanks, and medium tanks then in service.
The British also had a battalion of Matilda II infantry tanks that while slow, were also equipped with the 2-pounder;
An Indian brigade and Infantry tanks of 7th Royal Tank Regiment (7th RTR) would attack Nibeiwa from the west, as the 7th Armoured Division protected their northern flank.
The British persisted for much of the war on a dual track of development, retaining Infantry tanks to support the infantry and lighter, more mobile cruiser tanks for independent armoured formations.
Lieutenant-General Giffard Le Quesne Martel, head of the Royal Armoured Corps, described this concept as "the absorption of the armoured forces into the rest of the army," which required replacing an infantry brigade with a tank brigade equipped with infantry tanks.