High Quality Content by WIKIPEDIA articles! The Light Tank Mk VII (A17), also known as the Tetrarch, was a British light tank produced by Vickers-Armstrong in the late 1930s and deployed during World War II. The Tetrarch was originally designed as the latest in the line of light tanks built by the company for the British Army. It improved upon its predecessor, the Mk VIB Light Tank, by introducing the extra fire-power of a 2 pounder gun. The War Office ordered 70 tanks, an order that eventually increased to 220. Production was delayed by several factors, and as a consequence, only 100 to 177 of the tanks were produced.