On 15 September 1916 the battlefield changed forever. At Flers-Courcelette, during the brutal, bloody fighting on the Somme, the British army released a new weapon designed to combat the devastating power of the machine gun: the tank. Moving on caterpillar tracks and protected by plated armour, these slow-moving beasts had a terrific impact on their foe, causing huge chaos in the German army and spreading a massive amount of fear and terror: ‘the tank fear.’ The history behind the creation of the tank is remarkable. Almost from the beginning of the First World War, pioneering minds turned to trying to find a solution that would help protect soldiers from the dreaded machine gun fire as they advanced across No-Man’s-Land. An unlikely band of forward-thinkers, modernisers and engineers, among them Winston Churchill, attempted to tackle this problem. Their brainchild was to create an armoured, fighting vehicle fighting on caterpillar tracks and armed with both cannon and machine guns – a mobile death machine. And so the tank was born. The birth of the tank also resulted in the birth of a new division in the British army: the tank corps. Recruits for this new corps were taken from various walks of life and all were trained in every role very thoroughly. It was a perilous profession; for many these metal machines became their graves as the Germans inevitably discovered how they could successfully combat this new weapon of war. Warfare would never be the same again. In this original History Hit TV documentary renowned historian of armoured warfare David Fletcher MBE and David Willey, curator of the Bovington Tank Museum, discuss the First World War development of the tank. Why and how was the tank designed? How did it evolve over the course of the war? And what attributes were required of a Tank Man?