In the years between the accession of Edward I and the battle of Bannockburn, the English aristocracy served in expeditionary forces to Wales (1277–95), Gascony (1294–8), Flanders (1297–8) and Scotland (1296–1314). Moreover, during part of the same period, garrisons were maintained, at the expense of the exchequer, throughout the newly conquered territories within the British Isles as well as in the Crown's threatened enclaves in southwestern France. Fortunately, the names of thousands of men-at-arms who served on these campaigns and in these garrisons have survived. The aim of this book has been to reconstruct the military careers of these men, their connections to one another, the means by which they were recruited and the way that they performed their service in the king's armies. In essence, this has amounted to an investigation of mounted armoured warriors' experience of, and commitment to, the calling of arms, both as individuals and as members of groups.

The process of recruitment worked on three different but parallel levels: those of the individual soldier, the retinues within which he served, and the armies as a whole. The initial movement towards raising an army came from the king. Prior to 1277, there had been no campaign against an external enemy for two decades. Even after 1277, the first two-thirds of Edward I's reign saw little campaigning, other than the war of 1282–3, on an exceptionally large scale.