The battle of Agincourt is not only the most celebrated of all the great English victories of the Hundred Years War, it is also by far the best documented. It is the rich administrative archive that has come down to us for the campaign on which Michael Warner has based his analysis of two of the retinues that took part in it – those of Thomas, Duke of Clarence and Humphrey, Duke of Gloucester, Henry v’s younger brothers. Warner’s methodology is essentially that developed in the last twenty years by Andrew Ayton, which seeks through prosopographical analysis of the combatants to reconstruct the underlying structures so crucial to an army’s effectiveness in the field. Medieval armies, by their very nature, were ephemeral entities that lacked a permanent institutional structure of their own and relied for cohesion on the social authority and economic resources of their principal commanders. In the field, the effectiveness of a force turned largely on the commander’s day-to-day relations with his men and on the internal solidarity brought by the body of shared experience between the men themselves.

Warner’s findings highlight the contrasting backgrounds of the two dukes whose retinues he subjects to scrutiny. Both men were of the blood royal and both commanded large retinues on the Agincourt campaign: Clarence brought with him 980 men and Gloucester 796. Clarence, however, was a man of long military experience, whereas Gloucester, three years his brother’s junior, was not. Clarence had served his apprenticeship in arms in Ireland on campaigns in 1401 and 1408; he had served at sea in 1405, and in 1412 he had led a substantial expedition across France, ravaging the countryside between Normandy and Bordeaux. For his younger brother, the Agincourt campaign counted as his first taste of military service.

This essential difference, as Warner shows, found expression in both the composition and the social make-up of the two men’s retinues. Clarence’s company was marked by a high degree of internal cohesion, with over a quarter of his men-at-arms having had previous military experience, in some cases with him personally, and a high proportion of his sub-captains enjoying links with both the duke himself and with each other. The majority of Clarence’s sub-captains, moreover, were recruited from those parts of the country, principally the Midlands and north, in which he himself held lands, a feature that both reflected and reinforced the horizontal and vertical links that bound the force together. Gloucester’s company, by contrast, was lacking these powerful internal bonds. The novice duke, who had no established network of ties to draw on, had to build up his force from scratch, and the result was a less militarily experienced contingent which in all probability his father’s administrators had helped put together. In Gloucester’s case, as in Clarence’s, however, the ties of locality counted for something, with over half of the duke’s force coming from those parts of the country, mainly Essex and the south-east, in which he had lands. Internal solidarities, in other words, were not entirely lacking in the younger man’s force. What is striking is that neither of the two men apparently had any difficulty in making up the numbers that in their indenture with the king they had committed themselves to raising. Although the Agincourt campaign came at the end of a period of nearly thirty years in which hostilities with the French had been in abeyance, there was evidently a sufficient pool of potential combatants to make it possible to assemble a force that could compare with some of the largest of the Hundred Years War in size. Warner is sceptical of the view that the English gentry were becoming demilitarised by the beginning of the fifteenth century. Even if heads of families did not flock to Henry’s banner, he argues, their younger brothers and younger sons certainly did.

These are important conclusions that are bound to have implications for our understanding of the reasons for the English victory at Agincourt in 1415. Traditionally, the English triumph is attributed to the sheer mastery of Henry’s archers whose longbows, as in earlier encounters in the Hundred Years War, proved far superior to the crossbow used by the French. In the light of Warner’s study, however, it might also be argued that a possible reason for the victory is to be found in the solidarity of the English force and the experience and commitment of those who made up its numbers. It has been suggested, for example, that it was precisely the internal solidarities binding the English army at Crécy that made it such an effective fighting force in that battle, fought back in 1346. Such speculations about the possible broader implications of his findings, however, are ones that Warner chooses to resist, and perhaps rightly so. Ideally, more studies of this kind are needed before we attempt to weigh the social composition of the army in the balance against archery power among the reasons for Henry’s great victory in France.

The main strength of Warner’s book is the forensic thoroughness that it brings to the analysis of the rich administrative sources for the composition of the two retinues under review. The discussion of a couple of those classes of source material in particular – the muster rolls and the sick lists – is exemplary and adds greatly to our understanding of how these documents were put together. The book’s weakness is that the analysis of the social composition of the retinues begins to peter out when Warner turns his attention from the men-at-arms to the archers, whose lives, as he has to admit, are too ill-documented to allow us to form any meaningful conclusions about what held them together. This is a problem that any scholar attempting a sociological examination of the English forces in the Hundred Years War inevitably comes up against and is, alas, all too rarely able to overcome.

Warner is to be commended for offering us a pioneering study of the make-up and experience of a substantial part of the army responsible for one of the most spectacular English triumphs of the Hundred Years War. From the reader’s perspective it is unfortunate that the book, which originated as a doctoral thesis, bears in its prose too many of the signs of its gestation.