The Tank, Light, Mk VIII (A25), also known as the Harry Hopkins, after American President Roosevelt's chief diplomatic advisor, was a British light tank produced by Vickers-Armstrong during World War II. The Mk VIII was the last in the line of light tanks the company had built for the British Army, and was intended to be the successor of the previous light tank designed by Vickers-Armstrong, the Mk VII Tetrarch. A number of changes were made to the Mk VIII, most notably increasing its width, length and weight and also increasing the thickness of the armour. The design of the tank was submitted to the War Office in late 1941, with an initial order for 1,000 models being made by the Tank Board of the War Office in the same month, a number that increased to 2,410 in November. Production began