The Tank, Infantry, Mk IV (A22) was a heavy British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 infantry tank

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 tanks, to allow them to operate in...

 used in the Second World War

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, best known for its heavy armour, large longitudinal chassis with all-around tracks with multiple bogies, and its use as the basis of many specialist vehicles. It was one of the heaviest Allied

Allies of World War II

The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...

 tanks of the war. This series of tanks was named after Winston Churchill

Winston Churchill

Sir Winston Leonard Spencer-Churchill, was a predominantly Conservative British politician and statesman known for his leadership of the United Kingdom during the Second World War. He is widely regarded as one of the greatest wartime leaders of the century and served as Prime Minister twice...

, who was Prime Minister of the United Kingdom

Prime Minister of the United Kingdom

The Prime Minister of the United Kingdom of Great Britain and Northern Ireland is the Head of Her Majesty's Government in the United Kingdom. The Prime Minister and Cabinet are collectively accountable for their policies and actions to the Sovereign, to Parliament, to their political party and...

 and Minister of Defence

Minister of Defence (UK)

The post of Minister of Defence was responsible for co-ordination of defence and security from its creation in 1940 until its abolition in 1964. The post was a Cabinet level post and generally ranked above the three service ministers, some of whom, however, continued to also serve in...

 at the time, and had been involved with the development of the tank as a weapon during the First World War

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

.
Initially specified before the outbreak of the Second World War the (General Staff designation) A20

A20 heavy tank

The A20 heavy tank was a British Harland and Wolff tank which did not enter production but of which a downsized version by Vauxhall Motors became the A22 Churchill tank....

 was to be the replacement for the Matilda II

Matilda tank

The Infantry Tank Mark II known as the Matilda II was a British infantry tank of the Second World War. It was also identified from its General Staff Specification A12....

 and Valentine

Valentine tank

The Tank, Infantry, Mk III, Valentine was an infantry tank produced in the United Kingdom during the Second World War. More than 8,000 of the type were produced in 11 different marks plus various purpose-built variants, accounting for approximately a quarter of wartime British tank production...

 infantry tanks.