This book is not, in a formal sense, a history of the Tank Corps. Such a history must necessarily be impersonal in tone, and probably would aim at being judicial in manner - this last an almost impossible feat in our present state of knowledge. A more elastic form of narrative, based to some degree on my own experiences as a subaltern in the corps, appears to me to be preferable, as it will allow greater freedom of method and opinion and a large scope for the merely interesting and picturesque. Moreover, there already is in preparation (and likely to be in print before this appears) more than one semi-official history. It is my aim, therefore, to avoid giving a monotonous tale of battles which (to the lay mind) seem very familiar in type, and to describe instead in general terms the actual work of the tank in action at various stages of its career as an arm of the service, with its problems, its tactics, and its influence upon the war as a whole.
At the same time, it is necessary to use chronological facts as a scaffolding. The operations of the Tank Corps in the field, up to the date of the Armistice, fall naturally into two phases, marked very happily by a change in nomenclature.
