It did, for better and for worse. It's a very good book, and thought-provoking. But it has flaws and those flaws have infected aspects of the study of classical military history.

Keegan (1976) created what we refer to as the "face of battle" approach to military history. A definition of this approach is succinctly given by Kagan (2006 15): Firstly, the perspective of participants is used to relate events, secondly the writer attempts to convey sense of reality in details through examples, third the writer seeks to establish casual connection between soldiers reaction to weapons and the effectiveness and movement of their combat arms through the battle.

As the perspective of soldiers and the psychological aspect of battle is certainly lost in "general staff" narratives that only tell us about tactics and major events leading directly to a battle's outcome, Keegan's focus on the experience of the soldier and the importance of morale and fear is refreshing. However, what is his actual "method"? In the case of Waterloo and the Somme, he has the actual memoirs and accounts of soldier-participants to build his narrative. It is in Agincourt this method falls down: no such soldier-participant narrative account exists. As such, he constructs the soldier's experience from logical assumptions drawn from the technical characteristics of weapons and armour, and generalised human reactions to fear and weapons applied enmasse to units of soldiers. The logical leaps one must make to reconstruct the outcome of a battle from such a method, as opposed to relying upon the traditional perspective of the commander as viewed through the window of a tactical narrative, should suggest obvious flaws with the method. Put simply, one must assume that groups of men react similarly to fear and weapons, which is not necessarily the case.One must also assume this was the main determining factor in the battle's outcome, which is also not always the case, but one is limited to this view by adopting the narrow perspective of the soldier. Due to these flaws the "face of battle" approach often cannot tell us much if anything about what led to a particular outcome in a battle without relying on very broad assumptions- a command-centric approach is more appropriate for answering such questions. What the "face of battle" approach does do, if applied liberally, is emphasise the important of psychology, morale and fear as factors in battle, and help us "recreate" the experience.

The "face of battle" approach has been applied first to Greek warfare (Hanson 1989) and later to Roman warfare (Goldsworthy 1996). Due to the gaps in information that Keegan ran into at Agincourt and the ensuing difficulty of 'recreating' the experience of a soldier in battle in the classical period (due to lack of soldier-participant accounts), historians have dipped into other fields and theories to fill these gaps. The most obnoxious result of this is the application of modern, post WWII psychological theories to ancient combatants. As a result, Hanson compares the phalanx to a football team scrumming their opponent and Goldsworthy (and his continuators such as Daly) magically turn the Roman army into a modern institution wherein soldiers fought primarily for their "buddies" like Easy Company at Bastogne. The annoying thing about this modernising logic being applied to ancient warfare is that this "buddy theory" wherein soldiers are primarily motivated in battle by "not letting their buddies down", an idea pioneered by Americans (SLA Marshall 1947; Shils & Janowitz 1947) is not even cutting-edge stuff in modern military studies. Newer studies of soldier motivation emphasise that more enduring factors in combat are coercive discipline (Bartov 1992) or junior leadership (Rush 2001), which can keep soldiers in the fight whether they are buddies or not. Further, it is questionable whether Roman soldiers really saw their commilites as "buddies" at all: they might as easily have seen as competitors for distinction, and might have had very little concern for the safety of other soldiers (Lendon 2004, 2005).

The application of the "face of battle" approach has caused new-age historians like Goldsworthy, just as Keegan did in "The Face of Battle", to declare "traditional" historians had it all wrong as regards military history, but they haven't actually come up with a new method of analysis: they only have a new perspective. This new perspective is absolutely valuable, but it should not mean that the "old" style of battle narrative is now meaningless. Is it more important to recreate the experience of battle and relive it vicariously, full of possibly fantastic conceptions, or do we want to know why battles had certain results, which determined wars, which determined history? If you want the latter, you need to focus on tactics and the commander's perspective. If you want the former, and you're not particularly worried about the occasional bit of fantasy, then stick to the former. A blend between the two approaches is best.

Sources (regarding Keegan's influence on the study of classical warfare):

Kagan, Kimberly. The Eye of Command. Ann Arbor: University of Michigan Press, 2006.

Lendon, J.E. “The Roman Army Now.” The Classical Journal, Vol. 99, No. 4, 2004, 441-449.

Sabin, Philip. “The Face of Roman Battle.” The Journal of Roman Studies, Vol. 90, 2000, 1-17.

Wheeler, Everett. ”Book Review- Soldiers and Ghosts: A History of Battle in Classical Antiquity by J.E. Lendon.” The American Journal of Philology, Vol. 127, No. 2, 2006, 305-9.

honestly, it really did.

until the 1970s, military history was really confined to grand narratives. Keegan alongside guys like Denis Winter (Death's Men) brought the soldier's experience to the fore and made it a legitimate question that guys like Tim Cook have made their life's work. The Face of Battle, while certainly exploratory and thus quite flawed, kicked off a series of revisions in the historiography, especially of the World Wars.

more specifically, I think what Keegan did was really explore the limits of reclaiming the subaltern voice in military history. with his Agincourt example - which is literarily brilliant - he simply reconstructs what it might have looked like by playing out the logistics from a different point-of-view. I'm not sure that this is all that effective and empirically sound but it's a valiant effort to reconstruct the bloody reality of those soldiers bogged down in intimate fighting.

more successfully, in the example of the Somme, Keegan really the effects of both time and space on the soldier, especially with regards to technology. simply put, it's essential reading for any military historian. it's simply a different type of history than just oral histories can tell, with all the flaws of memory. as he puts it:

“Battle, for him [the soldier], takes place in wildly unstable physical and emotional environment; he may spend much of his time in combat as a mildly apprehensive spectator, granted, by some freak of events, a comparatively danger-free grandstand view of others fighting; then he may suddenly be able to see nothing but the clods on which he has flung himself for safety, there to crouch – he cannot anticipate – for minutes or for hours; he may feel in turn boredom, exultation, panic, anger, sorrow, bewilderment, even that sublime emotion we call courage.” (79)

beautiful writing, unique historiographical intervention, and a brave challenge to traditional military historians.