The reign of Edward III was, in military terms, a period of transition. At the beginning of his reign, the military systems inherited from Edward I were largely unchanged and their failures, obvious by the time of Bannockburn in 1314, had not been addressed. In 1327 the armies recruited in the young king's name for service in Scotland were dominated by foot soldiers levied on counties and liberties by commissions of array. The men-at-arms accompanying them were drawn primarily from the royal household and the households of the king's barons. By the time the first phase of the French war was concluded by the Treaty of Brétigny in 1360, English armies had started to assume a different character. The foot soldier had almost wholly given way to the mounted archer serving in mixed retinues with mounted men-at-arms. Although mounted, and thus able to travel swiftly on horseback, both men-at-arms and mounted archers generally fought on foot. The means by which they were recruited also changed: commissions of array gradually gave way to recruitment by military indenture, and paid service was the norm. Effectively, this privatised military recruitment: captains were responsible for gathering both men-at-arms and archers, usually in approximately equal numbers, for fixed periods in a clearly defined contractual arrangement. This change was gradual; although indentures had been known in the reign of Edward I, they were then only for garrison service, but the effects on the military participation of men from the shires and March of Wales were marked. The ill-equipped foot soldier was obsolescent by the 1340s and, whether they were levied from Welsh shires, Marcher lordships or English counties, their decline was a result of their inflexibility. Although foot soldiers were recruited after 1360, they were generally employed, as we shall see, in specialist roles.

Wales was subject to other changes. The generation which had witnessed Edward I's conquest, that had bolstered Edward II's authority, and that had led armies far greater than those ever assembled by any Welsh prince, came to the end of their careers and their lives. By the 1340s there was an identifiable change in attitude among the Welsh elite toward fighting in English wars. The leaders of Welsh society had always defined their position by military leadership. By the second third of the fourteenth century this tied Welshmen, militarily, to their lords.