While the testing and manufacturing of the tanks was underway, Estienne and the AS were developing their tactical ideas. David Johnson has argued that the French army after the Great War ‘viewed technology from an evolutionary perspective supportive of its existing doctrine’ and this is equally true of the army’s attitude during the war.2 In relation to armoured warfare, this sounds a rather conservative approach until the level of technology available during the period is considered, which was far too primitive to allow anything other than an incremental approach to integrating it into the army. As will be shown, it was certainly never developed sufficiently to justify a radical break with existing doctrine. This chapter considers the initial tactical thought in the AS during the course of 1916 and early 1917 and how this was put into practice in its battlefield debut during the Nivelle Offensive of 1917.