For secrecy, the six new tank companies were assigned to the Heavy Section of the Machine Gun Corps. The first use of tanks on the battlefield was the use of British Mark I tanks by C and D Companies HS MGC at the Battle of Flers-Courcelette (part of the Battle of the Somme) on Friday 15 September 1916, with mixed results. Many broke down, but nearly a third succeeded in breaking through. Of the forty-nine tanks shipped to the Somme, only thirty-two were able to begin the first attack in which they were used, and only nine made it across "no man's land" to the German lines. The tanks had been rushed into combat before the design was mature enough (against the wishes of Churchill and Ernest Swinton)"Sensing that tanks would only be effective if they involved an element of surprise, he pressed the government not to use them in small numbers in the Battle of the Somme. As he had put it in a memorandum in 1915, 'None should be used until all can be used at once'. Despite his objections, thirty-five (sic) tanks were used in September 1916, but to very little effect. 'My poor "land battleships" have been let off prematurely and on a petty scale,' he wrote." Havardi, J. The Greatest Briton: Essays on Winston Churchill's Life and Political Philosophy. Shepheard-Walwyn, 2010. and the number was small but their use gave important feedback on how to design newer tanks, the soundness of the concept and their potential to affect the course of the war.
