September 15, 1916: The tank makes its debut at the Battle of the Somme.
In an attempt to counter the dragging, senseless brutality of trench warfare, the British began developing armored vehicles they called “land ships” barely a year into the war. On September 15, at the Battle of Flers-Courcelette (a part of the Somme Offensive), a primitive but functioning combat vehicle called the Mark I made its debut on the battlefield. One British officer describes seeing a tank in action for the first time:
We heard strange throbbing noises, and lumbering slowly towards us came three huge mechanical monsters such as we had never seen before.
Only around fifty tanks were dispatched at Flers-Courcelette, and their debut was largely an experiment. While their sudden appearance did come as a surprise to the German forces, they did not give the British a very substantial advantage. They were slow (with a top speed of 3 km/hour), unreliable (many broke down to mechanical failures), and unwieldy (others were unable to maneuver the terrain). They did not, as British propaganda suggested they might, put an end to trench warfare and the war instantly (it lasted two more years). But they were new.
It was not until World War II that tanks became an essential part of warfare, and even then, it was not the British but the the Germans who used them to the greatest effect.