The Vickers No. 1 Tank was a British experimental tank developed in the 1920s. It was one of the early attempts to create a fully enclosed and fully traversable turret on a tank. This model was armed only with Hotchkiss machine guns (there also was a The Vickers No. 2 with 47mm gun).
The tank did not pass tests due to low speed and problems with the transmission (overheat).
Despite the ultimate failure to achieve a successful design, the Vickers No.1 can be considered among the early examples of modern tanks, incorporating design elements from the french tank Renault FT.