At the outbreak of the Hundred Years War in 1337 the Plantagenet dominions, in addition to England, comprised Gascony, Wales, parts of Ireland, the Isle of Man, the Channel Islands, and, theoretically, Scotland. The war would add to these lordships. Calais and its March were conquered in 1347; in 1360 the Treaty of Brétigny appended extensive lands to the duchy of Gascony, creating the short-lived principality of Aquitaine; Normandy was captured between 1417 and 1419; and the 1420 Treaty of Troyes established control over Paris and much of northern France.

This paper explores distinctions and common features in certain matters of policy and military practice that were applied throughout these dominions during the period of the Hundred Years War. In so doing it draws on a small area in the remarkably rich field of medieval military scholarship which has flourished so abundantly over the last twenty years or so. The quality and scale of this remarkable growth is in no small part due to the work of members of De re militari. For so long, military history was to be found in a niche area of scholarship, and rather a narrow niche at that, but the importance of medieval warfare and the medieval soldier, both in specific terms and in the ways in which it and they impacted upon political, diplomatic, and cultural affairs more widely, is now largely accepted.

This subject is, however, one shaped by historiographical divisions as well as developments, because it is, with certain notable exceptions, only relatively recently that scholars of the later Middle Ages have begun to think in holistic terms of the relationship between England and her dominions in France, Britain, and Ireland. Instead, work involving the various and, in some ways, disparate Plantagenet lordships has tended to comprise two – often distinct – areas of inquiry. These may be categorised, somewhat simplistically, as, first, insular studies, sometimes called the “New British History,” a term used to describe the collective analysis of Britain, Ireland, and the surrounding smaller islands – what J. A. Pocock called the Atlantic archipelago (and which he conceived as a subcontinental island group).