At the outbreak of the First World War, neither the tank nor the need for such a thing had been thought of.

By the middle of 1916, slightly less than 2 years later, the first operational tanks had been designed, built in sufficient numbers and rolled into action. This whole innovation is credited to the British, and British tanks were indeed the first to fire shots in anger, but a parallel development took place in France as well. As both nations had to be offensive in their actions, this was not surprising: both needed to penetrate ever-stronger German defences, and where possible avoid the sort of catastrophic losses suffered in the first years of the war.

Right from late 1914, the quest was on for something which could help the infantry reach, break in and then break through multiple defence lines. The first working vehicle – Little Willy – was revealed in September 1915.

With equal measures of support and resistance, development continued, resulting in the Mark I tank – the world’s first operational tank – which went into action for the first time at Flers during the Battle of the Somme in September 1916. Although small in nature this first action encouraged the army command to further support the tank and demand larger numbers.

After some early, marginally successful attempts at their own heavy tanks, the French agreed to a combined effort in which they would start developing light tanks, and the British, heavies. This split reflected the dual role perceived for tanks: slow, heavily armoured tanks to support the infantry in breaking through defensive lines and lighter, faster tanks for exploiting the breakthrough and raiding behind enemy lines, foiling attempts at counter-attack. At this stage, nobody thought that tanks would fight tanks, so simple machine guns were frequently the only armament.

Early on, mechanical reliability was a theoretical concept, with more vehicles failing through breakdown than were put out of action by enemy fire. Nevertheless, improvements were continually made to the tanks and to the tactics governing their use so that, in the ‘100 Day’ offensive in 1918, they made significant contributions to the defeat of the German Army.

Having been sceptical of tanks at the start, by late 1917, the Germans were rushing to produce their own and, pragmatically, were repairing captured British tanks and using them against their creators. Although they learned late, the Germans learned thoroughly, and just how thoroughly would be shown 20 years later.