A20 was a British tank design by Harland and Wolff to meet an Army requirement for an infantry tank that could replace the Matilda II and Valentine tank. It was designed in the expectation that conditions would be similar to those of the First World War.
The specification was produced by Superintendent of Tank Design at Woolwich with design by the Mechanization Board and passed to Harland and Wolff for detail work and to build a pilot.
Four pilots were ordered in February 1940. Two - A20E1 and A20E2 - were built. The first pilot took part in trials in June 1940. It was shipped from Northern Ireland to Vauxhall Motors (without a turret) in August; thereafter to Mechanical Warfare Experimental Establishment at Farnborough.
The Battle of France indicated that trench warfare was not going to be the case in the Second World War. A new specification, A22, was drawn up and Vauxhall who had been engaged to find a suitable power plant - their Bedford "twin six" engine - for the A20 were i