Amongst the first ever mass-produced tanks in history, the British Mk IV has been classified as one of the most successful heavy tanks to have fought in World War I. Mechanically similar to its predecessors, the Mark IV embodied various improvements, suggested by experience with earlier variants, including better armour, improved weapons and easier transportation. It proved its worth at the landmark battle of Cambrai in November 1917, when 460 Mark IVs were deployed for the first time against the enemy with great effect. Arguably changing the nature of war on the Western Front, the Mark IV was one of the first vehicles in the world to partake in a tank duel when, in 1918, it met the German A7V in combat. Drawing on a wealth of previously unpublished photographs and new information on its operational abilities, this fascinating exploration of the British Mk IV includes detailed descriptions of the tank and its variants, such as the mine-clearing tank, the Tadpole tail device, and the tank created for towing airships, to complete the picture of this crucial vehicle and its deployment on the Western Front.