The Vickers 6-Ton Tank or Vickers Mark E was a British light tank designed as a private project at Vickers. It was not purchased by the British Army, but was picked up by a large number of foreign armed forces. It was licensed by the Soviets as the T-26. It was also the direct predecessor of the Polish 7TP tank.
Additional Information: en.wikipedia.org/wiki/Vickers_6-Ton