Edward I's achievement in recruiting large numbers of the gentry for his wars should not obscure the fact that the responsibility for conducting the king's campaigns still lay primarily with the upper ranks of the aristocracy. The scale of the Crown's ambitions led to the enlistment of many families that had never previously seen active service; but it was the traditional warrior elite who provided the human and financial resources that made this mobilisation programme possible. The earls, barons and bannerets of the realm were Edward's chief henchmen in his attempts to conquer and colonise Wales and Scotland; and it was their assistance that he and his son relied upon most heavily when attempting to defend their ducal inheritance in southwestern France. Indeed, without the support of the large retinues brought to war by their magnates, the kings of England would have been powerless to meet their enemies in open battle. Before proceeding to look at the identities of this elite, their careers in arms and the duties that they performed, this chapter will begin with two preliminary and closely related questions: how did contemporaries refer to men who held positions of military command, and what can these terms tell us about the different kinds of military leadership exercised by the aristocracy in Edwardian England?