The Infantry Tank Mark II, best known as the Matilda, was a British infantry tank of the Second World War.
The design began as the A12 specification in 1936, as a gun-armed counterpart to the first British infantry tank, the machine gun armed, two-man A11 Infantry Tank Mark I. The Mark I was also known as Matilda, and the larger A12 was initially known as the Matilda II, Matilda senior or Waltzing Matilda. The Mark I was abandoned in 1940, and from then on the A12 was almost always known simply as "the Matilda".
With its heavy armour, the Matilda II was an excellent infantry support tank but with somewhat limited speed and armament. It was the only British tank to serve from the start of the war to its end, although it is particularly associated with the North Africa Campaign. It was replaced in front-line service by the lighter and less costly Infantry Tank Mk III Valentine beginning in late 1941.
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.
In 1934 Hobart, the then "Inspector, Royal Tank Corps", postulated in a paper two alternatives for a tank to support the infantry. One was a very small, heavily armoured, machine gun-armed model that would be fielded in large numbers to overwhelm the enemy defences. The other was a larger vehicle with a cannon as well as machine guns and heavier armour proof against enemy field artillery. Vickers designed a tank to a General Staff specification based on the first option as the A11 Matilda. Within the limitations of military finances, the Master-General of the Ordnance, Hugh Elles, went for the smaller machine gun tank and the larger cannon-armed version did not proceed. This requirement was passed to Vickers-Armstrongs which had a prototype (A11E1) but with armour proof against current anti-tanks guns ready by September 1936.
The first suggestion for a larger Infantry Tank was made in 1936, with specification A12. The design was produced by the Royal Arsenal, Woolwich, and Vulcan Foundry was selected as the manufacturer. A12 used a number of design elements of the A7, a medium tank that was built in limited numbers in the early 1930s whose mechanical layout was used for many following designs. With its greatly increased armor, a lack of power was seen as a problem. The solution was to use two AEC straight-six water-cooled diesel engines, used in London buses, providing up to 87 hp each. These were linked along a common shaft. Suspension was to use the 'Japanese Type' bell crank suspension used on the A7.
Matilda II A12E1 prototype
Vulcan received a contract for two wooden mock-ups and two mild-steel prototypes in November 1936. The first mock-up was delivered in April 1937 and the A12E1 prototype in April 1938. The prototypes proved excellent in a 1,000 miles (1,600 km) test, resulting in only a few changes to improve the gearbox, suspension and cooling. When war was recognised as imminent, production of the Matilda II was ordered and that of the Matilda I curtailed. The first order was placed shortly after trials were completed, with 140 ordered from Vulcan in June 1938.