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. Over its lifetime it went from a riveted construction to entirely welded, and from a petrol powerplant to a safer, less ignitable, two stroke diesel engine produced by GMC. It was supplied to the USSR and built under license in Canada. Developed by Vickers, it proved to be both strong and reliable.