Introduction: the French armoured force: the Artillerie Spéciale -- "It takes a lot of stuff to kill a German": French material responses to the Western Front -- "Our sacrifice will not be in vain": the Artillerie Spéciale in the Nivelle Offensive 1917 -- The battle behind the lines: aftermath of the Nivelle Offensive -- "A masterpiece of tactics": the Battle of Malmaison -- "A charming toy": the light and heavy tanks and other projects -- The charge at Chaudun: the tank regulations and the introduction of the Renault light tank into service -- All the perfect engines of modern war 1: the battles of Cutry & Antheuil and Directive No. 5 -- The greatest day since the Marne 2: the Battle of Soissons, July 1918 -- The Battle of Somme-Py: Champagne, swansong of the medium tanks -- Conclusion: an event as important as the invention of gunpowder and cannon?