British Infantry Tanks: The A11 Infantry Tank Mk. I (Matilda), A12 Infantry Tank Mk. II (Matilda II)

The Infantry Tank was a concept adopted by Britain in the late 1930s as a new European war began to seem inevitable and the British Army was recognised as having a critical shortage of tanks.
It was, like so many other British ideas, born out of a compromise. Visionaries within the British Army wanted an entirely new type of tank: fast, agile and hard-hitting, this would be capable of forming independent armoured formations. Others, more conservative, wanted nothing more than an updated version of the British tanks used during World War One: slow, but heavily armoured and primarily designed to be able to cross the broken ground of no-man's land and attack the fortifications and trenches beyond.
The visionaries expected to fight an entirely new type of armoured war. The conservatives confidently anticipated re-fighting World War One. The compromise was to develop tanks suitable for both roles. Cruiser Tanks would be fast and capable of engaging enemy armour. Infantry Tanks would move at no more than the speed of a brisk walk but would be heavily armoured.
Britain would create four Infantry Tanks before and during World War Two. Three weren't particularly effective, though one of them would become the most-produced British tank of the war. The fourth version, the Mk. IV Churchill, started badly. Early versions were unreliable and its first use in combat was a disaster. It came close to being cancelled, but instead it would prove to be one of the most successful and versatile British tanks of World War Two.
This is the story of the only British Infantry Tanks, from the flawed Mk. I to the mighty Mk. IV. It also covers four other attempts to create an even more effective Infantry Tank, though none of those went beyond the construction of prototypes.