The detailed study of Henry of Lancaster's expedition in 1345–46 has attempted to add to our understanding of the army, the expedition, and the careers and lives of the individuals who took up arms in Lancaster's retinue. A close scrutiny of the royal administrative records has provided fresh insights into the military preparations prior to the army's embarkation, and has thrown new light on the shipping of the earl's expeditionary force. Overall the assembling of Lancaster's army was impressive and the time in which it was mobilised is a testament to the efficacy of England's military organisation. A new analysis of the arrival and departure of different retinues and military contingents in the duchy has highlighted the changes in the army's composition and, indeed, the changes in the nature of warfare over the course of the expedition. The decision to send infantry-based reinforcements to Aquitaine in 1346 was clearly a response to Lancaster's anticipation of siege warfare on account of the arrival of the duke of Normandy's huge army in the duchy. The earl's need for soldiers who possessed the ‘shooting power’ to defend a castle's walls is borne out by the arrival of the contingent of 300 Welshmen which was entirely made up of archers.

It has been shown that 1345 was a crucial year for military developments in England, not least in the Crown's use of the indenture system to recruit magnates for military service. That three retinue captains in Lancaster's army accounted for their service directly at the Exchequer is indicative of the development of the indenture system which, by the time of the Agincourt campaign (1415), was used to recruit all royal armies. The Crown's use of contract management fulfilled an important role in the financing of multiple expeditionary forces in the mid 1340s and demonstrates the professionalism of the royal administration. A systematic study of the extant pay records has shown that the finances of Lancaster's army were administered efficiently, despite the fact that the multi-front warfare launched by Edward III inevitably put an enormous strain on the royal system of finance.