The British Mark I tank was first used in combat at the Battle of Flers-Courcelette on 15 September 1916. The engagement formed part of the wider Somme offensive on the Western Front.
Britain developed the Mark I in response to the trench deadlock. Its rhomboid shape and fully tracked design were intended to cross trenches, crush barbed wire, and move over shell-torn ground while protecting crews from small-arms fire. The “male” version carried naval guns and machine guns, while the “female” version relied on machine guns.
The first deployment was experimental and difficult. Of 49 tanks sent to the Somme, only 32 were ready to attack, and just nine reached the German lines. Many broke down or became stuck, but the appearance of the vehicles startled German defenders and demonstrated that tanks could support infantry. The Whippet and Mark IV came later; the Mark II was also not the model used in this first combat operation.