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...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 and was copied almost exactly by the Soviets as the T-26. It was also the direct predecessor of the Polish 7TP tank. By the start of World War II it was the second most common tank design in the world after the Renault FT-17.