Britain and France first developed tanks in 1915 as a way of navigating the barbed wire and other obstacles of no-man's land while remaining protected from machine-gun fire. British Mark I tanks first went into action at the Somme on 15 September 1916, but did not manage to break the deadlock of trench warfare. The first French employment of tanks, on 16 April 1917, using the Schneider CA, also failed to live up to expectations. In the Battle of Cambrai (1917) (November to December 1917) British tanks were more successful, and broke a German trenchline system, the Hindenburg Line.