The Mark I was a development of Little Willie, the experimental tank built for the Landships Committee by Lieutenant Walter Wilson and William Tritton in the summer of 1915. The Mark IV was used en masse (about 460 tanks) at the Battle of Cambrai in November 1917 The Mark V, with its much improved transmission, entered service in mid-1918.

With the exception of the few interim Mark II and Mark III tanks, it was followed by the largely similar Mark IV, which first saw combat in June 1917. The Mark I entered service in August 1916, and was first used in action on the morning of 15 September 1916 during the Battle of Flers-Courcelette, part of the Somme Offensive. It is regarded as successful in many respects, but suffered from many problems owing to its primitive nature. It was developed to be able to cross trenches, resist small-arms fire, travel over difficult terrain, carry supplies, and to capture fortified enemy positions. Born of the need to break the domination of trenches and machine guns over the battlefields of the Western Front, it was the first vehicle to be named 'tank', a name chosen as an expedient to maintain secrecy and to disguise its true purpose. The British Mark I was a tracked vehicle developed by the British Army during the First World War, and the world's first combat tank. Mark II, Mark III, Mark IV, Mark V, Mark V*, Mark V**, Mark VI, Mark VII, Mark VIII, Mark IX, Mark X, Gun Carrier Mark IĨ (commander/brakesman, driver, two gearsmen and four gunners)Ģ3.6 miles radius of action, 6.2 hours endurance

William Tritton, Major Walter Gordon Wilson A British Mark I 'male' tank near Thiepval on 26 September 1916, fitted with wire mesh to deflect grenades and the initial steering tail, shown raised

Russian modern tanks mk.4