Tank

From 1915 a committee set up by the Admiralty worked on a 'landship' in Britain. For secrecy the workers were told they were building water tanks, which gave the vehicle its English name. The first Mark Is at Flers-Courcelette were slow and unreliable, and many stuck or broke down, but they took the Germans by surprise. The French first used their tanks in April 1917.

The breakthrough came at Cambrai in November 1917, when several hundred British tanks, working with infantry and artillery, broke through the Hindenburg Line. In 1918 tanks, above all the light French Renault FT with its rotating turret, became a regular part of Allied attacks. Germany built only about 20 of its own A7Vs; on 24 April 1918 at Villers-Bretonneux the first tank-versus-tank duel took place.