Infantry tank The infantry tank was a concept developed by the British and French in the years leading up to World War II . Infantry tanks were tanks designed to support the infantry in the attack . To achieve this they were generally heavily armoured compared to the cruiser tank s , to allow them to operate in close concert with infantry even under heavy gun fire . The extra armouring came at the expense of speed , which was not an issue when supporting relatively slow moving infantry . Once the infantry tank - supported attack had broken through heavily defended areas in the enemy lines , other tanks such as cruisers , or light tanks , were expected to exploit their higher speed and longer range to operate far behind the front in order to cut lines of supply and communications . Background . 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 Percy Hobart and Captain B . H . Liddell Hart . Comparisons to other tank types . Using later terminology , the infantry tank has been compared to a heavy tank , while the cruisers were compared to mediums , lights , or even armoured car s . This comparison can be misleading though : particularly as the infantry tank was never intended to have the same anti - tank capabilities as a heavy tank . The infantry tank was distinctly different from either the " heavy tank " or " breakthrough tank " concepts , although some pre - war multi - turreted heavy tanks such as the Soviet T - 35 and German " Neubaufahrzeug " ( both taking some of their inspiration from the Vickers A1E1 Independent tank prototype - an idea which was abandoned by the War office in the late 1920s for lack of funding ) were similar , and with similar doctrines for their use . The " Neubaufahrzeug " was considered too slow for Blitzkrieg tactics and fell from favour . German ( and to some extent Soviet ) wartime doctrine shifted towards faster medium and heavy tanks fighting large multi - tank battles , with the role of the infantry tank in assaults taken by simpler self - propelled artillery . An important difference , however , was that heavy tanks were generally very well armed , while infantry tanks were not necessarily better - armed than other tanks . For example , the Soviet KV - 1 heavy tank and British Matilda infantry tank were deployed at about the same time in 1940 . These two tanks had similar levels of armour protection and mobility , but the KV was far more heavily armed than the Matilda . In British practice , the main armament of the infantry tank went in three phases . The pre - Dunkirk British Army Matilda I had only a single machine gun , a compromise forced by the lightness of its chassis . The Matilda II gained a capable anti - tank capacity for its time , with the 40mm 2 pounder , but these were only issued with solid - shot ( i . e . non - explosive ) for anti - tank use and was of little use for artillery close - support of infantry . The ultimate evolution of the British infantry tank concept began with the Churchill MkI , where a hull - mounted 3 inch howitzer could support infantry assaults with HE shells . As the increasing size of tanks , and their turret ring diameters , allowed such a howitzer to be turret - mounted in vehicles such as the Crusader CS & Centaur CS . History . UK . Since the infantry tanks were to work at the pace of the infantry units , which would be attacking on foot , high speed was not a requirement and they were able to carry heavier armour . The first two purpose - designed infantry tanks , the Mark I " Matilda " and Mark II " Matilda " were armed with a heavy machine gun and QF 2 pounder anti - tank gun respectively . These two saw action in the Battle of France . They were followed by the Valentine and Churchill designs . The Valentine proved to be difficult to develop further but the Churchill went through successive variants and served up to the end of the war . As British cruiser tank designs developed into larger tanks with more powerful engines , they could carry larger guns and more armour yet still achieved high speeds . At the end of the war the cruiser tank lineage led to the " universal tank " in the form of the Centurion . In practice the British did not operate only infantry and cruiser tanks . Lack of production capacity meant the large scale adoption of US medium tanks . France . In the French Army the infantry tank role was filled largely by the Renault R35 , a light tank , which was similar to the Matilda I in terms of armour , but better armed . In practice , although able to resist hits from tanks and anti - tank guns , and designed for good , albeit slow , cross - country performance , the separation of tank functions into specialised areas such as infantry and cruiser types was not effective . Invariably the cruisers ended up meeting enemy tanks in combat , while the infantry tanks were the only ones present when a breakthrough was accomplished . The infantry tank idea faded as tank design progressed during the war . It was eventually replaced outright with the general acceptance of the universal tank idea . The concept was also employed by the other big tank - producing nation of the 1930s : the Soviet Union , as exemplified by the T - 26 tank . The T - 26 was a light tank assigned to Infantry units and thus fulfilled the infantry tank role , but in it had the relatively thin armour of light tank , but with a potent 45 mm gun . Their BT tank s were the fast cruiser types . Germany had its separate " Panzerwaffe " and the German Infantry used phased out Panzerkampfwagen I ' s in its Independent Tank Brigades . This is often seen as reflecting some explicit doctrine ; in reality it was caused by a simple lack of budget , tank production not having any priority . When more money became available the Sturmgeschütz III was taken into use by the Artillery , in its original role of infantry close support vehicle - the counterpart of the allied Infantry tanks . Despite the concept of splitting of tanks into infantry and cruiser roles being an instance of the general economic principle of division of labour in mechanization , during World War II its application in mechanized warfare proved to be hugely inefficient in terms of technical development , production , maintenance , logistics , and — worst of all — tactical flexibility . Therefore it was not surprising that during the war , it was progressively abandoned by all the major belligerent countries . US . For political reasons , the US Army was not permitted " tanks " in the years before WWII and so the tracked AFVs that it did develop were termed " Combat Car s " instead . This attitude , and their deployment with cavalry units , encouraged their treatment as light tanks . When the first medium tank design appeared , it was a confused design that had some features of the already outdated multi - turret designs : multi machine - gun mounts , light anti - tank weapon , but omitted the close - support howitzer that was by now an important feature of British and French designs .