The Offensive Defensive in Medieval Strategy [Rogers]

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The Offensive/Defensive in Medieval Strategy.1 
 
Published as “The Offensive/Defensive in Medieval Strategy,” From Crecy to Mohacs: Warfare in the Late Middle Ages 
(1346-1526). Acta of the XXIInd Colloquium of the International Commission of Military History (Vienna, 1996) (Vienna: 
Heeresgeschichtliches Museum/Militärhistorisches Institut, 1997): 158-171. 
 
 
Clifford J. Rogers 
Department of History 
United States Military Academy 
West Point, NY 10996 
 
 
 
Invincibility lies in the defence; the possibility of victory in the attack. 
--Sun Tzu 
 
If the defensive is the stronger form of warfare, but has a negative aim, then it follows of itself that one must avail 
oneself of the defensive only so long as weakness makes this necessary; and one must abandon it as soon as one is 
strong enough to pursue the positive aim. 
--Clausewitz. 
 
 
 
 
 
 Let me begin this essay in a somewhat unorthodox fashion, by asking the reader to ponder, for a few 
moments, a question: what single factor had the greatest impact in determining defeat or victory on the late 
medieval battlefield? Was it numbers? The experience of the troops? The tactical skill of the commanders? 
Weaponry? Something else entirely? 
 Since my own particular specialty is the fourteenth-century phase of the Hundred Years War, my natural 
initial answer to that question would be that the best way to ensure victory would be to be certain that you had made 
arrangements well in advance to be sure that, when the moment of combat arrived, you were.... English. But that 
response, of course, would not have been very helpful to a fifteenth-century French soldier being introduced to arms 
and seeking instruction on how to fight war with success. Indeed, it would not even be very satisfactory for a 
historian considering the Hundred Years War as a whole, since in the later years of the war the French were more 
 
1 My thanks to Kelly DeVries for his useful comments on an earlier draft of this article, and to the Association of Graduates of 
the United States Military Academy for a grant which enabled me to present this study at the ICMH conference. 
 Rogers - Offensive/Defensive in Medieval Strategy - 2 
 
 
than able to hold their own against the English, at Castillon and Formigny for example. Nor would it cast much 
light on the dynamics of battle in, say, late medieval Bohemia or Morea. 
 
 A better answer to the question--- indeed, the best answer I know of--- was given late in the fifteenth 
century by the French soldier Jean de Bueil in his well-known work Le Jouvencel. His answer was elegantly 
simple: to win, stay on the tactical defensive. Let me allow him to make his point in his own words: 
 
 A formation on foot should never march forward, but should always hold steady and 
await its enemies on foot. ... A force which marches before another force is defeated, unless God 
grants it grace. And, therefore, take up a position as advantageous as possible, and do it early.2 
 
De Bueil then goes on to support his generalization with a substantial array of historical evidence: 
at Agincourt, the French had to march a long way over the fields to reach their enemies, so that they lost 
their array and were defeated. At Verneuil, the French similarly marched forward and lost their order, 
partly because of horsemen falling back through their formation, and so they lost again. At Baugé, the 
Duke of Clarence advanced against the French; and so the English were defeated, and Clarence was killed. 
At Patay, the English marched in front of the French, and so were defeated before they could take up a 
proper position. At Formigny, the English again marched in the face of the enemy, and were again 
defeated. When the Swiss fought the French at St.-Jakob, they took the tactical offensive, and were wiped 
out. At Castillon, the numerically superior English marched up against the French, who held back and 
awaited them calmly; and therefore, says de Bueil, therefore the French defeated them.3 
All of these examples are drawn by de Bueil from the wars of the French in the fifteenth century, 
but the same principle holds true quite well both in other regions--- the regular defensive successes of the 
Hussites in the 1420s and 1430s being a prime example--- and also for the fourteenth century: consider the 
 
 
2Jean de Bueil, Le Jouvencel, ed. Léon Lecestre (Paris: SHF, 1887), 2:63. "une bataille à pié ne doit point marches; mais doit 
tousjours attendre ses ennemiz pié coy. Car, quant ilz marchent, ilz ne sont pas tous d'une force, ilz ne pevent pas tenir 
ordonnance. Il ne faut que ung buysson pour les despartir. Une puissance qui marche devant une autre puissance est desconfite, 
si Dieu ne lui fait grace. Et, pour ce, prengne place d'avantaige qui pourra et de bonne heure." 
3Ibid., 63-66. 
Fernando
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 Rogers - Offensive/Defensive in Medieval Strategy - 3 
 
 
French at Courtrai, Crécy, Poitiers, and Nicopolis; the Scots at Dupplin Muir and Halidon Hill; the French 
and Castilians at Aljubarrota; the Montfortians at Auray; the bishop of Liége’s men-at-arms at Vottem,4 
the troops of the Duke of Athens at Cephissus in 1311. At all these fights, the side which took the tactical 
offensive lost. It did not take until Agincourt, much less until Castillon, before this was recognized. 
Already at Auray in 1368, Sir John Chandos is reported to have observed that "one quite often sees--- I say 
it without hesitation--- that it goes ill with the side that attacks first."5 
 
 Why was it so advantageous to stand on the defensive? Well, there were a number of reasons. Generally, 
the side on the defensive was the one which had chosen the battlefield, and the choice was usually made to its own 
advantage.6 
 Sometimes the advantage was so great that the enemy would refuse to attack unless the defenders accepted 
a summons to come down from their strong position and fight on fair ground.7 But even if the defenders did their 
best to do as they were often asked to do in the formulaic challenges preceding a battle--- choose a place where the 
fight would not be impeded by rivers, fortifications, or other obstructions8--- it would be nearly impossible for them 
to find a place which did not offer some sort of impediment to an army attempting to advance, in step, in a solid 
formation of pikemen arrayed, to borrow a common medieval hyperbole, "in such close order that one could hardly 
throw an apple among them, without its falling on a bascinet or a lance."9 
 Incidentally, I realize I was going against the orthodox opinion10 by adding the words "in step" to that last 
sentence, but I suspect that by the late fourteenth century it was normal for heavy infantry to march in step on the 
 
4On this interesting but little-known battle of 1346, see Jean le Bel, Chronique de Jean le Bel ed. Jules Viard & Eugène Déprez. 
(Paris: SHF, 1904), 2:140-1. 
5Cuvelier, Bertan du Guesclin, ll. 5875-78: "Laissiez-nous...tenons nos conroiz sans nous adesfouquier; / Car on voit bien 
souvent, je le di sans cuidier, / Qu'il meschiet à celui qui assault le premier." 
6Cf. Flavius Renatus Vegetius, The Earliest English Translation of Vegetius' De Re Militari ed. Geoffrey Lester. (Heidelberg: 
Carl Winter Universitätsverlag, 1988), III.13, p. 134: "Hit longith to euerich duke to knowe and to wite that a wel chosen place 
to fi[gh]te ynne is a grete cause of victorie"; Le Jouvencel, 154. 
7E.g. Jean le Bel, Chroniques, 1:66; Lopez de Ayala, Crónicas de los Reyes de Castilla (Madrid: Biblioteca de Autores 
Españoles, 1919), 1:554. 
81339 Campaign Diary, in Oeuvres de Froissart ed. Kervyn de Lettenhove (Bruxelles, 1870, etc.), 18:87-8; cf. Jehan de Waurin, 
Recueil des Chroniques ed. W. Hardy (London: Rolls Series, 1868), 2:195 
9Used for example by Froissart to describe the Montfortians' arrayat Auray. Oeuvres, 7:46. 
10Cf. Michael Roberts, "The Military Revolution, 1560-1660," in The Military Revolution Debate ed. C. J. Rogers (Boulder: 
Westview, 1995), 30. 
 Rogers - Offensive/Defensive in Medieval Strategy - 4 
 
 
battlefield, and indeed it was likely common practice by the late twelfth century, if not even earlier.11 I reach this 
conclusion mainly because there are a number of chroniclers' descriptions of armies advancing "by the short step" or 
"without at all breaking order, by the good step;" "by the good step... without turning to the right nor to the left, and 
do[ing] everything as one act and in one way;" etc.-- note the constant use of the definite article before "step." 12 
Furthermore, the medievals were certainly aware, via Vegetius, of the Roman practice of marching in step during 
battlefield maneuvers and during peacetime drill, and of the contribution this technique made to Roman tactical 
prowess.13 Thus, in the absence of strong evidence that medieval armies did not march in step, it seems reasonable 
to make a tentative conclusion that they did. 
 Marching into battle in the extremely tight order described above (whether or not in step) was, for troops 
who did not drill regularly, a difficult enough enterprise even on a perfectly open battlefield. The most negligible 
irregularity of terrain could prove a serious problem for attacking troops: as de Bueil observes, "when [infantry] 
march, they are not all of one force; they cannot keep their order. Only a bush is needed to break them up."14 The 
consequences of any disruption could be very serious. As Christine di Pisan observed near the start of the fifteenth 
century, 
 
 
11The twelfth-century date I base on the following passage from Wace's Roman de Rou, (before 1175) which I think strongly 
suggests a formation of archers marching in step, even though (it might be argued) on the same grounds I would have to allow for 
the knights' horses marching in step: 
 "Cil a pié aloent avant, / sereement, lor ars portant, / chevaliers emprés chevalchoent / qui les archiers aprés gardoent; / 
cil a cheval e cil a pié, / si com il orent commencié, / tindrent lor eirre e lor compas, / sereement, lor petit pas, / li un l'autre ne 
trespassout / ne n'apreismout ne n'esloignout..." [Emphasis added.] 
 Cited in Matthew Bennett, "Wace and Warfare," in Anglo-Norman Warfare ed. Matthew Strickland (Woodbridge: 
Boydell and Brewer, 1992), 248. Bennett's excellent article provides a favorable assessment of Wace's understanding of military 
matters. Wace's text is offered some support by al-Heweri's description of the "Franks," (c. 1211), which describes European 
infantrymen as customarily marching--- according to Ritter's translation of the original into German--- "schrittweise." H. Ritter, 
"La Parure des Cavaliers und die Literatur über die ritterlichen Künste," Der Islam, 18 (1929), 147. 
12Jean le Bel, Chroniques, 65: "les batailles alassent avant vers les anemis, tout bellement, le petit pas" [the same phrase is used 
much earlier in the Roman de Brut par Wace, ed. Le Roux de Lincy (Rouen: E. Frère, 1836), ll. 3,181-3 (Jà nus d'als n'i 
desrangera /... Cil en iront le petit pas)]; Froissart, Oeuvres, 10:31 (Beverhoutsveld), "toujours aller devant eulx, sans point 
desrouter, le bon pas..."; 10:154, "entrelachés de vos bras par quoy on ne puist entrer en vous, et alés toudis le bon pas et par 
loisir devant vous sans tourner à destre ne à senestre, et faites tout d'un fait et d'un chemin" [emphasis added]; also 7:46, "tout 
bellement le pas"; 10:169, "le grosse bataille des Flamens tout en une, qui aprochoit durement et venoit le bon pas tout serret." 
13Vegetius, 1.8; The Earliest English Translation of Vegetius' De Re Militari, 58. 
14See note 1, above; also Le Jouvencel, 154: “pou petit qu[e une haye ou fossé] soit il fait grand bien.” Cf. Andrew of Wyntoun, 
Orygynale Cronykil of Scotland, ed. David Laing (Edinburgh: Historians of Scotland, 1872), 2:475, on the Scots at Neville's 
Cross: "At hey dykis assemblid thai, / And that brak gretly thaire aray; / Tharfor thai war swne dyscumfyte"; also Froissart, 
Oeuvres, 11:162. 
 Rogers - Offensive/Defensive in Medieval Strategy - 5 
 
 
 The leader or chief of the army should order his divisions according to the advantages of 
the place and the field where the battle is expected to take place, and order that his men should 
march in close order and without breaking ranks.... Two great evils, says [Vegetius], can follow from 
a disordered formation: one is that the enemies can more easily break into it; the other is that the 
formations may be so compressed that they cannot fight. Thus it is necessary to keep a formation in 
ranks, and tight and joined together like a wall.15 
 
Both of these problems emerged, for example, at Agincourt. On the one hand, English archers and 
men-at-arms took advantage of the gaps created by the recoiling French cavalry to "break into" the 
formation of the advancing French infantry, and wrought much havoc as a result. When medieval 
chroniclers report that one side lost a battle because it did not maintain good order--- as they very often do--- 
it is usually to this outcome that they are referring.16 But the second "evil" arising from bad order, 
compression, could have even worse consequences. At Agincourt, many men in the center of the French 
formation, squeezed between the English to their fore and their flanks and their own countrymen pressing in 
from behind, suffocated in helpless misery.17 This latter phenomenon was surprisingly common in 
medieval battles. Geoffrey le Baker says that at Crécy many of the French were smothered in the press, 
though unwounded, and a large number of sources say that at Dupplin Muir the Scots lost more casualties to 
 
15Christine de Pisan, Fais et Bonnes Meurs du Sage Roy Charles V in Petitot, Collection complète des mémoires relatifs a 
l'histoire de France, 5:394: "Dit oultre ledit livre que le duc ou chevetaine de l'ost doit ordonner ses batailles, selon l'avantage de 
la place et le champ où la bataille doit estre, et ordonner que ses gens voisent serrez et sans desrouter; et s'aucun y a qui 
communément soit coustumier de desrouter, soit bouté hors; car il pourroit nuire aux autres. Deux grans maulx, ce dit, peut 
ensuivre de bataille desroutée: l'un est que les ennemis y peuent entrer plous légiérement; l'autre est que les batailles sont si 
empressées que ilz ne peuent combatre: pour ce est neccessaire tenir ordre arrengié, et comme un mur serré et joint ensemble." 
Cf. ibid., 409. 
16Storie Pistoresi (MCCC-MCCCXLVIII) [Rerum Italianorum Scriptores, XI, vol. 5], 216: "perchè stavano con poca ordine"; 
Froissart, Ouevres, 10:154: "nostre ennemy furent tos desconfy et ouvert à la bataille de Bruges par nous tenir drut et fort 
ensamble que on ne nous peuist ouvrir"; Lopez de Ayala, Crónicas, 2:104: "la cosa del mundo porque ome mayor aventaja 
puede tomar de su enemigo es ponerse en buena ordenanza...en dos batallas que los Reyes de Francia, mis señores, el Rey Don 
Phelipe é el Rey Don Juan, ovieron con el Rey Eduarte de Inglaterra, é con el Principe de Gales, su fijo, perdieron las batallas los 
Reyes de Francia, é fué todo por non tener buena ordenanza en su batalla." [Emphasis added.] 
17John Keegan's otherwise excellent treatment of the battle of Agincourt in his The Face of Battle does not mention that the 
compression of the French formations was so severe that it led to numbers of men being smothered, but this fact is well attested. 
E.g., see the chronicle of John Hardyng, a participant in the battle: "The prsse [sic] of enemies did supprise / Their owne people, 
ye mo were dede through prsse / Then our men might have slain.” 
 Rogers - Offensive/Defensive in Medieval Strategy - 6 
 
 
suffocation than tobow or sword.18 One of the most vivid descriptions of such a catastrophe is provided by 
Froissart in his narrative of the battle of Rosebeke: 
 
 There they put these men-at-arms into such a state of compression that they were 
helpless, and could not draw back their arms, nor their pikes, in order to strike or to defend 
themselves. There the majority of them lost their strength and breath, and tumbled one over 
another; and their blood ceased to flow, and they died without striking a blow.... There was a 
mountain, a heap of dead Flemings, very long and very high; and such a small amount of 
blood flowed out as had never been seen before from such a large battle and number of people 
killed as there were there. And this was because so many were crushed and suffocated in the 
press, for out of them no blood spurted.19 
 
Even in less extreme cases, compression caused substantial problems for the afflicted army, since it 
imposed a severe disadvantage in the hundreds of individual conflicts which determined the result when 
formation struggled with formation.20 
So, let me propose a syllogism which recaps the argument I have so far made: 
 
 1. A medieval infantry formation which had its array disrupted was likely to be defeated 
if it encountered an opposing force in unbroken array. 
 
18Crécy: Geoffrey le Baker, Chronicon, 84. Dupplin Muir: Gesta Edwardi Tertii, 106; British Library MS Faustina B V 
(Historia Roffensis), fo. 62v; Bodleian Library MS 240 (Historia Aurea), fo. 560; Wyntoun, Orygynale Cronykil, 2:388; Thomas 
Gray, Scalacronica ed. Joseph Stevenson (Edinburgh: The Maitland Club, 1836), 160. 
19Froissart, Oeuvres, 10:170-172: "Là les missent ces gens d'armes en tel destroit que il ne se pooient aidier, ne ravoir leurs bras, 
ne leurs plançons, pour férir, ne eux deffendre. Là perdoient li pluiseur force et alainne, et tresbuchoient l'un sus l'autre, et 
s'estanchoient et moroient sans cop férir... Là fu un mons et un tas de Flamens ochis, moult lons et moult haulx; et de grant 
bataille et de fuisson des gents mors, sicom il y ot la, on ne vey oncques si peu de sanc yssir que il en yssy. [Variant:] Et 
c'estoient au moyen de ce quil estoient beaucoup d'estains et estouffés dans la presse, car iceulx ne gettoient point de sang." 
 It is interesting to note that the high wall of dead bodies reported at Agincourt, which Keegan dismisses almost out of 
hand, was also described by Froissart at Rosebeke and by many chroniclers at Dupplin Muir. This leads me to conclude that it 
was probably a genuine phenomenon, one which resulted from this compession/suffocation effect. 
 It is also worth noting that medieval French sources often use "la presse" as a synonym for the thick of the battle; e.g. 
see the Roman de Brut, l. 3184. 
20Froissart (Oeuvres, 11:174) suggests that this contributed to the defeat of the French vanguard at Aljubarrota. Cf. John 
Keegan, The Face of Battle (Harmondsworth: Penguin, 1978), 100. 
 Rogers - Offensive/Defensive in Medieval Strategy - 7 
 
 
 2. Any unit of foot which advanced against a steady enemy was likely to become 
disordered in the process (especially, but not only, if were being shot at by English archers or by cannon on 
the way in); while an army remaining in place would have no difficulty in maintaining its formation. 
 3. Therefore, advancing against an enemy was likely to lead to defeat. 
 
Or, as de Bueil put it, “I tell you as a maxim that whenever men on foot make a frontal attack on 
their enemies, those who march lose, and those who stay in place and hold steady, win.”21 
 
Now, like any "rule" of history, this one had exceptions. But the key point is that late medieval 
commanders generally accepted the principle that (to quote Christine di Pisan again) "enemies well arrayed 
and in good order, if they are attacked, will not be easy to defeat,"22 and, therefore, they typically went to 
great lengths to avoid having to take the tactical initiative. 
Up until the late 1420s in France, and substantially later than that in most of Europe, the advantages 
enjoyed by the defensive on the battlefield were matched by equally strong advantages for the defensive in 
siege warfare. Until the flowering of the fifteenth-century "Artillery Revolution,"23 the defenders of a 
strong, well-garrisoned and well-equipped fortress clearly had the upper hand in siege warfare: as one 
popular manual of the early fifteenth century stated, in such a case the besieged ought to be able to hold out 
"until they were rescued, or their enemy had been given a good thrashing and departed."24 
The superiority of the defensive in siege and battle alike produced a situation in which there was a 
high level of what might be called "strategic inertia." Those whose strategic aims were to maintain the 
 
21 Le Jouvencel, 153: “Je vous dy pour maxime que toutes et quanteffoiz que gens à pié marchent contre leurs ennemys front à 
front, ceulx qui marcheront perdront, et ceulx qui demeureront pié coy et tiendront ferme, gaigneront.” And again on p. 189: 
“Car tous ceulx qui marchent à pié, se desordonnent et se mettent hors d’alaine et communement sont desconfitz.” It should be 
noted that de Bueil had the opposite view when it came to cavalry vs. cavalry fights: then it was most advantageous to attack. 
22Christine de Pisan, Fais et bonnes meurs du sage roy Charles V, 412, if the enemy "sont les premiers assaillis, et ilz sont bien 
assemblez et en bel ordre, ilz ne sont pas de legier vaincus”; cf. Le Jouvencel, 154. 
23See Clifford J. Rogers, "The Military Revolutions of the Hundred Years' War," in The Military Revolution Debate ed. C. J. 
Rogers (Boulder: Westview, 1995). 
24London: Royal Armouries MS I-34, fo. 37v: "piss man sie entrettet oder ir feind mit guten taedingen do von geweist hetten." 
Cf. Das Feuerwerkbuch von 1420. 600 Jahre Deutsche Pulverwaffen und Büchsenmeisterei ed. Wilhelm Hassenstein (Munich: 
Verlag der Deutschen Technik, 1941), 69. 
 Rogers - Offensive/Defensive in Medieval Strategy - 8 
 
 
status quo had a much simpler task than those who aimed to effect changes.25 To use the Clausewitzian 
terminology of the epigram at the head of this article, the defense may be inherently stronger, but it can only 
accomplish a "negative aim;" to accomplish a "positive aim" requires going on the offensive. The side 
pursuing defensive objectives could simply adopt a Fabian strategy like the one which his French advisors 
advocated to King John of Castile in 1387: 
 
We will make war wisely, by garrisons, for two or three months, or for a whole season, 
if need be, and allow the English and Portuguese to chevauchée through Galicia and elsewhere, 
if they can. If they conquer some towns, what of it? We will recapture the towns immediately, 
once they have left the area. They will only have borrowed them. ... So the best way to 
decimate and defeat them is to decline to fight them, and let them chevauchée wherever they 
may.26 
 
 This advice summarized the strategy used with great success by Charles V and DuGuesclin against 
the English after the resumption of the Hundred Years War in 1369, which in turn owed much to the Scots' 
traditional methods of dealing with the invasions of their stronger southern neighbors. 
In this strategic milieu, one might expect to see aggressive warfare become rare--- for if an invader 
cannot force a battle without accepting a high probability of defeat, and cannot conquer and hold down 
territory except by a laborious, ruinously expensive, and exhausting process of conducting long siege after 
long siege, what can he do? 
Yet we know, of course, that there was no shortage of aggressive warfare in fourteenth- and 
fifteenth-century Europe. There were English troops fighting in Ireland, Scotland, France, Flanders, Spain 
and Portugal; French armies in Gascony, Iberia, Scotland,Italy, the Low Countries, and Bulgaria; etc., etc. 
Furthermore, the invaders were often very successful; this is particularly true of the English under Edward 
 
25See the observations of Pierre Dubois and Francesco Guicciardini, quoted in Rogers, "Military Revolutions," 24. 
26Froissart, Oeuvres, 12:139-140: "Nous guerroierons sagement par garnisons deux ou trois mois ou toute ceste saison, se 
besoing est, et lairons les Anglois et les Portingalois chevauchier parmy Gallice et ailleurs, se ils pèvent. Se ils conquièrent 
aucunes villes, quoy de ce? Nous les reaurons tantost reconquises, mais que ils soient partis hors du pays. Ils ne les feront 
seulement que emprunter...Et ainsi nous ne les povons mieulx gaster, ne desconfire que de non combatre et les laissier 
cheavuchier partout où ils pèvent"; Cf. ibid., 12:304-5, 4:424. 
 Rogers - Offensive/Defensive in Medieval Strategy - 9 
 
 
III from Halidon Hill to Brétigny, even though his army's tactical system was especially ill-suited to 
offensive action. This is not so paradoxical as it may at first glance seem, for a little reflection will reveal 
that Edward's armies were so successful on the battlefield precisely because they did almost always manage 
to fight on the tactical defensive. This was the case for the English armies at Dupplin Muir, Halidon Hill, 
Crécy, and Poitiers, not to mention Agincourt and Verneuil. But that leads us to another question: if 
medieval commanders were aware of the tactical superiority of the defensive, and if the superiority of the 
defensive in siege warfare made it very difficult for an enemy to employ a gradualist strategy of conquest 
and occupation, why would a strategic-level defender be willing to incur the greatly increased risk of defeat 
which came with initiating a battlefield attack? 
Answering that question correctly was perhaps the most important duty of a good medieval 
strategist.27 If you want a battle, but don't want to have to take the tactical offensive, how do you compel 
your enemy to attack you, despite his knowledge that he will be accepting a major disadvantage by doing so? 
Various commanders were faced with this problem in dozens of campaigns in this period, and their solutions 
show a few clear patterns. 
The first and simplest method to get an enemy to assume the burden of attack was a challenge to 
his honor. If an adversary was sufficiently confident in his own strength, or sufficiently proud or rash, or 
unfamiliar with the difficulty of assailing a steady formation of infantry, he might be willing to deliver battle 
in order to punish an aggressor and to protect his own honor and reputation. Thus, after a somewhat token 
effort to force the English to take the tactical offensive, the French at Agincourt allowed themselves to be 
pulled into advancing against the motionless English; for this mistake, as we have seen, they paid dearly. 
James Douglas hoped that his incursion into England in 1327 would be enough to provoke the English into 
giving battle even after he had taken up a virtually unassailable defensive position. Edward III, in his first 
campaign in France, fully expected that the simple fact of his entry into France would suffice to persuade 
Philip VI to attack him. Battle, after all, was seen as a form of judicial duel between nations, and once a 
 
27It is worth noting, in passing, that this situation--- clear superiority of the defensive both in battle and in siege--- existed also in 
the Early Modern period after the development and spread of the trace italienne fortress in the early 16th century. Thus, much of 
what I say below concerning the century and a half after 1300 may also be applicable, mutatis mutandis, to the c. 1530-1789 
military era. 
 Rogers - Offensive/Defensive in Medieval Strategy - 10 
 
 
gauntlet was thrown down, it was expected that a chivalrous knight would accept the challenge and fight, 
"come what may."28 
When pursuing battle in such a way, a commander had to pay close attention to the etiquette of 
insult. Symbolic gestures helped--- in the last-mentioned case, for example, Edward chose to make his entry 
into France on the Feast of St.-Denis, the patron saint of the French monarchy. Letters would be sent, so 
that the enemy could not pretend to be ignorant of the challenge. These might be courteous, appealing to the 
enemy's chivalry, humanity, and religion, like the one sent by Edward III from the siege of Tournai in 
1340.29 They might be gently reproving, like the one the same king sent to his adversary a year earlier: 
Tell Philip, said Edward to a French prisoner he released to serve as a messenger, (which seems, by the way, 
to have been the customary way of conveying such communications)30 "that he and his people have not 
been at all courteous, nor done what they ought to, in thus keeping waiting men who were striving daily" to 
do what the French king had asked in his recent letter, in which he had offered to give battle.31 The letters 
might take a more threatening tone: come and do battle, or "see such things as you have never seen 
before."32 Of course, the challenge should ideally make it quite clear that the challenger was offering to 
accept battle, not to deliver it: the disadvantages of the tactical offensive had to be left to the enemy. Thus 
we see the frequent, almost formulaic, use of some version of the challenge sent by the Scots from their 
strong defensive position in the Weardale in 1327: "The King and his council saw well that they were in his 
kingdom, and had burnt and devastated it; if this annoyed the King, he might come and amend it, for they 
would stay there as long as they liked,"33 or alternately of the one sent by Henry of Lancaster to the French 
in 1356: "My lord answered that he had come into these parts in order to do certain business, which he had 
 
28Cf. the advice of Guillame de Machaut and François de Montebelluna to "fais ce que dois, adviegne que peut," cited in Clifford 
J. Rogers, "Edward III and the Dialectics of Strategy, 1327-1360," Transactions of the Royal Historical Society, 6th Ser., 4 
(1994), 93. For Edward’s expectations in 1339, see his letter in Avesbury, Gestis Mirabilibus, 304. 
29Avesbury, Gestis Mirabilibus Edwardii Tertii, 314-15. 
30Also used by the Scots at Weardale in 1327 (Thomas Rokesby) and by Edward III in Picardy in 1355 (Marshal Boucicaut). 
311339 Campaign Diary, in Froissart, Oeuvres, 18:91: "qu'il, ne sa gent, ne furent mie cortoises et ne feirent lour deveir par ensy 
targer la gent qui furent travaillés de jour en autre et de ceo qu'il avoient requis par lour lettres." Similarly, Philip's letter to 
Edward in 1346: "vos, qui terram vultis conquirere, si bellum affectatis sicut assertis, oblationem istam refutare non debetis." 
Walter of Hemingburgh, Chronicon Domini Walteri de Hemingburgh ed. H. C. Hamilton. (London: English Historical Society, 
1849), 3:424. 
32Jean le Bel, Chronique, 1:160: "ilz luy feirent sçavoir qe s'il ne venoit combatre à eulx par deça la riviere, il verroit encore 
chose laquelle n'avoit veu." 
33Jean le Bel, Chronique, 1:54. 
 Rogers - Offensive/Defensive in Medieval Strategy - 11 
 
 
now well completed, thanks be to God, and was now returning from where he had done it; and, if the said 
King Jean of France wanted to disturb him on his way, he would be ready to meet him."34 We can hear 
echoes of these retorts, for example, from Jean de Hainault in 1326,35 from Edward III in 1346 and 
1355,36 from Buckingham in 1380,37 and (in a scene made famous by Shakespeare but also to be found in 
the contemporary sources) from Henry V in 1415.38 
The basic problem with all this was that it only worked if the enemy's sense of honor could be 
made to overrule his good sense. When a commander's advisors--- or his own native caution--- could 
emphasize both thestrategic and tactical superiority of the defensive, and support their arguments with the 
weighty authority of Vegetius' De re militari, they could often convince their leader that discretion is the 
better part of valor, and that the enemy should not be attacked. Charles V of France was among the 
strongest supporters of this cautious policy: "Let them go their way," he is said to have ordered the nobles 
who wanted to assail the army which Buckingham led through France in 1380, "Let them go their way: they 
will destroy themselves, and all without battle."39 Of course, Charles had his knowledge of Crécy and 
Poitiers to support this choice; but even before those dramatic proofs of the superiority of the tactical 
defensive had sent out their shock waves, Philip VI in 1339 had been willing to accept the counsel of 
caution and refrain from attacking Edward III when the latter invaded France, even though the French king 
 
34Letter in Robert of Avesbury, De Gestis Mirabilibus Regis Edwardi Tertii ed. E. M Thompson (London: RS, 1889), 464: 
"Sur quey mounseignur lour respoundy qil est venuz en yceles parties pur certains busoignes feare, lez quels il avoit bien comply, 
Dieu mercy, et fust en returnaunt la ou il avoit affaire; et, si le dit roy Johan de Fraunce luy voleit destourber de son chemyn, il 
serroit prest de luy encountrer." 
35At the meeting of Queen Isabella's tiny "invasion force" with Edward II's army: "Jehan de Hénaut et ses deux chevaliers 
ordonnèrent leurs gens en conroy, comme pour actendre la bataille, et disrent se le roy les assalloit ilz se deffenderoyent." 
Recueil des Historiens des Gaules et de la France t. XXI (1226-1328). Ed. MM. Guigniaut et de Wailly. (Paris, Imprimerie 
Impériale, 1855), 129. 
361346: Twice during the Crécy chevauchée: British Library, MS Cotton Faustina B V, fo. 91v ("Ait tunc Philippus: 'Et ubi 
potero eum invenire?' Dominus rex respondit, 'Ubi ipse luminaria [of burning towns] accensa viderit...'"); PRO C66/219/m. 21d; 
Calendar of Patent Rolls (1345-48), 516-17 (Therefore if you wish, as your letters purport, to do battle with us and protect those 
whom you claim as your subjects, you can now show it: at whatever hour you approach you will find us ready to meet you in the 
field, with God's help, which thing we desire above all else for the common good of Christendom, since you will not deign to 
tender or accept any reasonable terms for peace. But we do not consider it advisable to [allow ourselves] to be cut off by you, or 
to let you choose the place and day of battle). 1355: Jean le Bel, Chroniques, 2:214: "dire à vostre seigneur que je ay ars son païs 
jusques icy, pour tant que je cuidoye qu'il venist estaindre les flamesches, et sy luy dirés que je l'attendray ci trois jours; si me 
trouvera s'il veult venir; et s'il ne vient, je m'en iray ainsy que je suys venu." 
37Froissart, Oeuvres, 9:269. 
38Waurin, Recueil des Chroniques, 2:195. Cf. Henry V, Act III, Scene VI. 
39Froissart, Oeuvres, 9:278: "Layés-leur faire leur chemin; il se degasteront et perderont par eulx meismes et tout sans bataille." 
Cf. Jean de Noyal, "Fragments inédits de la Chronique de Jean de Noyal, abbé de Saint-Vincent de Laon (XIVe siècle)" ed. A. 
Molinier. Annuaire-bulletin de la Société de l'histoire de France, (1883), 271, 275. 
 Rogers - Offensive/Defensive in Medieval Strategy - 12 
 
 
had always sworn that Edward and his army would not spend a single day in France without having a 
battle.40 Philip's failure to play the lion's role by attacking the invader was seen by many in and out of 
France as a severe blow to his reputation--- many French knights took to wearing caps of fox fur to 
symbolize their "detestation and mockery" of his "Renardie"--- but some of the less hawkish of his subjects 
praised his wisdom: 
 
Perhaps this was the best and the most fitting counsel, and the healthiest, [wrote 
one chronicler,] because the said King of England, who had come to conquer the realm of 
France, which he claimed as his own, departed from it, and defeated himself without 
doing anything to his profit, and little to his honor.... So it seems that it would have been 
tempting fate to put so many good knights in peril without very great necessity.41 
 
Thus, the general seeking to draw his enemy into giving battle had to maximize the harm which 
refusing to deliver battle would do to the opponent's honor, and create the "very great necessity" which 
would justify the risk of launching an attack. 
 
One way to put the enemy into such a situation was to lay siege to a key city within his territory 
until it was brought to the verge of surrender. That could give the defender a strong incentive to gather a 
rescue force to break the siege; and if the besieger had set things up properly, that would compel the 
relieving army to take the tactical initiative. Edward III, for example, used this strategy successfully in 
1333, when his siege of Berwick compelled the chary Scottish army to attack the force he had arrayed atop 
Halidon Hill; and he tried unsuccessfully to put Philip VI in the same position with the sieges of Tournai in 
 
40Letter of Edward III in Avesbury, Gestis Mirabilibus, 304: Philip "avoit toutz jours jurez, a ceo qe nous avoiems novels, qe 
nous ne ferroms jammes demeore une jour od nostre ost en Fraunce qil ne nous durroit bataille." 
41Bodleian MS Fr. d. 4, fo. 178: "Et par aventure fut ce le meilleur et le plus meur conseil et le plus sain car ledit Roy 
d’Angleterre qui estoit venu pour conquerre le Royaume de France, qui sien estoit sicomme il disoit, s’en departi et se desconfist 
li mesmes sans faire point de son proufit et pou de son honneur.... Se semble que se feust estre tempter Dieu de mettre tant de 
bonne chevalrie en peril sans tresgrant neccessite." Cf. Vegetius, Earlierst English Translation of Vegetius' De re Militari, 158: 
"Gode dukes ne fighteth neuere opounlyche in feeld but thei ben idryue therto by sodeyn hap or grete nede," and Lopez de Ayala, 
Crónicas, 2:100: "estaba en acuerdo de aventurar toto su fecho por batalla, ca non avia otro remedio." [Emphasis added.] 
 Rogers - Offensive/Defensive in Medieval Strategy - 13 
 
 
1340 and of Calais in 1346-7.42 Ten years later, the Black Prince tried to use the siege of Romorantin to 
draw Jean II in to battle.43 The same strategy probably lay behind John o'Gaunt's siege of Muros in the 
1380s, and it was certainly the need to relieve Castillon which persuaded Talbot to undertake his disastrous 
attack of 1453. 
There were substantial problems with this means of pressuring an enemy into attacking, however. 
The first difficulty was that, because of the superiority of the defensive in siege warfare throughout most of 
this period, it could be very expensive in time and money to carry on a siege up to the point where the 
defenders were ready to make a surrender compact. Especially if the target were a major city--- and if it 
were not, then the likelihood of the enemy accepting the disadvantages of the tactical offensive in order to 
rescue it was not great--- the siege generally had to be maintained until the defenders were on the verge of 
starvation, like the inhabitants of Rouen in 1418-19, who held on for six months until the provisions they 
had laid in were all consumed, and with them the dogs, cats, mice, horses and rats of the town ("For [thirty 
pence] went a ratte/ For [two] noblys went a catte./ For [six pence] went a mous/ they lefte but fewe in any 
house" says the poem of one eyewitness).44 Henry V had expended a vast amount of treasure in wages and 
munitions in order to take matters thus far, seeming to bear out Pierre Dubois' early-fourteenth century 
argument that "A castle can hardly be taken within a year, and even if it does fall, it means more expenses 
for the king's purse and for his subjects than the conquestis worth."45 
Indeed, such expenses, or simply logistic problems, might force the besieger to abandon the siege 
before the garrison could be brought to negotiate for surrender, in which case he would be left only with 
great expenses and small gains: this was the case for Edward III at Tournai in 1340 and Cambrai in 1339. 
Even once these difficulties were overcome, though, the ball still was left in the defender's court. He might, 
regardless of "sad and pitiable" missives from the besieged, still refuse to accept the danger of battle on 
disadvantageous terms, preferring the limited loss of a single city to the potentially crippling effects of a lost 
 
42See my forthcoming book, War Cruel and Sharp: English Strategy under Edward III, 1327-1360, chs. 4, 8, 11. 
43Galfridi le Baker de Swynebroke [Geoffrey le Baker] Chronicon ed. E. M. Thompson. (Oxford: Clarendon, 1889), 141. 
44John Page, "Poem on the Seige of Rouen," The Historical Collections of a Citizen of London in the Fifteenth Century, ed. J. 
Gairdner, (London: Camden Society, 1876), 148. 
45Quoted in J. F. Verbruggen, The Art of Warfare in Western Europe During the Middle Ages. From the Eighth Century to 
1340. (Amsterdam: North Holland Publishing Co., 1977), 273. 
 Rogers - Offensive/Defensive in Medieval Strategy - 14 
 
 
field battle.46 Thus, for example, though the French raised large armies in order to break the sieges of 
Tournai in 1340, Calais in 1346-7, and Rouen in 1418-9, in each case they decided not to hazard a defeat by 
attacking the besiegers' armies. 
Of course, the prospect of attacking a besieging army could be a formidable one, since the 
besiegers were likely to be protected by their own fortified camp, which would greatly magnify the already 
powerful advantage of the defensive. At Calais, Philip VI so dreaded a recapitulation of Crécy that he was 
unwilling to take the risk of attacking Edward III's entrenched encampment, despite the city's inherent 
strategic importance, and despite the urgent pleas of the garrison--- which pleas had reached the French king 
courtesy of Edward III, whose men had captured the garrison commander's last report, which Edward had 
then read and forwarded to the French under his own privy seal, along with an additional personal letter in 
which he too urged his adversary to come to the town's rescue.47 
When neither the strategic need to rescue Calais nor the English king's appeal to his cousin's honor 
proved sufficient to induce Philip to take the tactical offensive, Edward tried working the other side of the 
equation. He had already done all he could to raise the price Philip would have to pay for passivity; now he 
made an effort to lower Philip's perception of the cost of taking action. He agreed to come out from his 
entrenchments and fight on a fair field chosen by a committee of eight knights from each side. Despite this 
offer, Philip declined to give battle,48 for he recognized the unstated assumption of Edward's proposal. 
With the strategic situation as it was, with Calais about to fall, and considering the concession Edward was 
making in giving up his dug-in position, once the armies faced off it would certainly be Philip rather than 
Edward who was expected to attack. The Valois king realized that, for the reasons outlined above, whatever 
battle site the two sides might agree on would not be a "fair" one so long as the onus of attack remained with 
the French. 
 
46As Vegetius advised, (here in a late-13th century translation): "for euerich opoun werre other contek withynne twey houres or 
thre stryvinge hit is endid and finischid, and than the hope and trist of victorie of thilke partie that is ouercome holliche is 
ouerslipped and aslaked, ... [so] gode lederes and wise cheuenteynes ne fightith noght bletheliche with open bataille and in open 
feeld yif there be open drede of perel." Flavius Renatus Vegetius, The Earliest English Translation of Vegetius' De Re Militari 
ed. Geoffrey Lester (Heidelberg: Carl Winter Universitätsverlag, 1988), III.9 (p. 126). 
47See my forthcoming War Cruel and Sharp, ch. 12. 
48Ibid. 
 Rogers - Offensive/Defensive in Medieval Strategy - 15 
 
 
The most recent scholarly account of the siege of Calais doubts the veracity of the English king's 
proclaimed willingness to come out of his siege works to fight, since "no sensible person in Edward's strong 
position could have accepted" such a proposal.49 But as we know, Edward was in a difficult strategic 
position. As Clausewitz and Sun Tzu have both observed, the defense is the stronger form of warfare, but 
only the offensive can achieve a positive aim, and Edward's war-aims were far from being merely status 
quo.50 For strategic reasons, then, Edward wanted a battle; for tactical reasons, he needed to fight on the 
defensive. If he could achieve both these aims by leaving his entrenchments and taking up a position on an 
even field, it would be perfectly "sensible" for him to do so. And, conversely, it was prudent for Philip to 
decline an engagement. 
 
Prudent, but not kingly. As John Fortescue observed not long after the end of the Hundred Years 
War, "All the power of a king ought to be applied to the good of his realm, which in effect consists in the 
defence of it against invasions by foreigners... Therefore, a king who cannot achieve [this] is necessarily to 
be adjudged impotent."51 Which brings us to the third major method for persuading a defending army to 
launch an attack on an invading force: devastation. As H. J. Hewitt and others have pointed out, 
devastation was, even more than siege and far more than battle, the normal work of a medieval army on 
campaign.52 Devastation and plundering served many purposes for an invader. Most directly, they 
enriched him and his men at the expense of the enemy's people. Second, pillage and destruction reduced the 
means available for the enemy to use against the invader--- directly, by taking away the food and supplies 
which might be used to provide for the defending army, and indirectly, by emptying the purses from which 
the tax revenues which paid for the defending army's wages were drawn. Third, they inflicted direct 
 
49Jonathan Sumption, The Hundred Years War, v. 1: Trial by Battle (London: Faber and Faber, 1990), 580. 
50Clausewitz, Vom Kriege, 6.1 (Bonn: Dümmler’s Verlag, 1952), 513: "die verteidigende Form des Kriegführens is an sich 
stärker als die angreifende...Ist die Verteidigung eine stärkere Form des Kriegführens, die aber einen negativen Zweck hat, so 
folgt von selbst, dass man sich ihrer nur so lange bedienen muss, als man der Schwäche wegen bedarf, und sie verlassen muss, 
sobald man stark genug ist, sich den postiven Zweck vorzusetzen." Sun Tzu, Art of War, tr. Samuel B. Griffith (Oxford: OUP, 
1963), IV.5 (p. 85): "Invincibility lies in the defence; the possibility of victory in the attack." 
51John Fortescue, De Laudibus Legum Anglie ed. and tr. S. B. Chrimes. (Cambridge: CUP, 1942), 81; cf. 35. 
52 H. J. Hewit, The Organization of War under Edward III, 1338-62 (Manchester: Manchester U. P., 1966). 
 Rogers - Offensive/Defensive in Medieval Strategy - 16 
 
 
"punishment" on the enemy people, and thus harm to the enemy ruler: whatever the enemy would wish you 
not to do, says Vegetius, do just that.53 
It has long been recognized that an invader could, by this "work of havoc," put heavy political 
pressure on the victims of the devastation. As Clausewitz notes, in order to make an enemy accede to your 
will, you must create a situation in which continuing the war will be more painful to him than accepting the 
sacrifice required by your peace terms. Thus, with the chevauchées of the English in fourteenth-century 
France or the raids of the Scots into England in the reign of Edward II, the explicit message of the 
destructionwas "give in to our political demands, and we will stop inflicting this pain on you." In both 
those cases, the message was received and accepted: the English ratified the "cowardise pees" of 
Northampton in 1328, acknowledging Scotland's claim to independent sovereignty, and the French at 
Brétigny in 1360 agreed to sign over suzerainty of greater Aquitaine to Edward III. 
There is, of course, an alternate way, rather than giving in to the enemy's demands, to put an end to 
an invader's depredations: confront him during the course of his pillaging, attack him, and defeat him. It 
might be natural to assume that this would be rather easy to do when, as in those two situations, we are 
looking at a case in which a relatively small, weak nation is launching attacks into the territory of a richer, 
more populous, more powerful neighbor--- especially given the advantages of the defender outlined above. 
The normal way of resolving the conflict between that generalization and the two specific cases cited is to 
emphasize the invaders' great mobility: the English could not stop the Scottish raids, runs the argument, 
because the Scots were too fast; the French could not stop the English, because the English were too fast. 
(Though just how the English, living off the land, stopping for plunder, and traveling through a distant and 
hostile land, could be able to count on outpacing a cavalry-based army like the French host, operating on its 
own home territory, is generally not fully explained.) 
One problem with this formulation is, of course, that the English did catch up to the Scots in 1327--
- because the latter had stopped to wait for their enemy, then sent the captured English esquire Thomas 
Rokesby back to Edward III's army to guide it to them, and to announce to Edward that "they are as eager to 
fight with you as you are to fight with them"--- but the English did not defeat them.54 The French did 
 
53De re militari, III.28. 
54 Jean le Bel, Chronique, 1:63. 
 Rogers - Offensive/Defensive in Medieval Strategy - 17 
 
 
catch up with Edward III in 1346--- after he halted at Crécy to wait for them--- and did manage to come to 
grips with the Black Prince in 1356. Especially in the latter two cases, this has usually been put down to a 
failure of generalship on the part of the invaders. Yet, with the understanding of the advantages accruing to 
the tactical defensive developed earlier in this paper, we can see that there is no reason to see the outcome of 
the battle of Crécy or Poitiers as merely a fortuitous escape from a bad situation.55 In each case, the 
situation of the English army, though it was outnumbered, poorly supplied, and tired, was not so bad as it 
seemed, because in each case the onus of the tactical offensive lay with the French. Just as the strategic 
defender could be forced to take the tactical offensive in order to rescue a besieged city, so too could he be 
impelled to take the tactical offensive in order to put an end to the work of the invader's torch and sword. 
The aggressor, pursing his "positive aim" through an offensive strategy, took advantage of the greater 
strength of the defensive when it came to the moment of confrontation by creating a situation in which the 
immediate positive aim was forced on the defender because immediate status quo was unsatisfactory to the 
defender: his city was about to fall, or his people were being despoiled, and the despoilers were positioned 
to escape unpunished. 
Or at least, that is what happened if things went well for the aggressor, if he conducted his 
campaign more effectively than did his adversary. The defender, obviously, would do his best to avoid 
having the burden of delivering battle thrust upon him. If possible, indeed, he would try to create a situation 
in which the strategic aggressor was forced also to be the tactical aggressor. The first of those two 
possibilities was of course easier to achieve: all it took, really, was a strong will---enough self-control to 
ignore the demands of honor, the chastisements of shame, and the plaints of the oppressed--- and a 
willingness to accept a certain amount of destruction which the enemy could inflict before he "defeated 
himself" and departed. Here we are back to the successful policy of Philip VI in 1339-40 and the sound 
advice offered to the King of Castile in 1387. 
The other possibility, securing the advantages of the tactical defense for the strategic defender, was 
simple in concept but difficult in execution. The trick was to cut off the invader or pin him in place, and 
 
55 See my “Edward III and the Dialectics of Strategy, 1327-1360,” Transactions of the Royal Historical Society, 6th. ser., 4 
(1994). 
 Rogers - Offensive/Defensive in Medieval Strategy - 18 
 
 
then just stay the course until he had no choice but to attack or to starve.56 Constable d'Albret had 
succeeded in doing this in 1415, by blocking Henry V's road to Calais, but his overconfidence and his failure 
to account fully for the superiority of the tactical defensive (he hadn't, after all, read this paper) led him to 
squander the opportunity thus gained. As Jean le Bel reports, the English tried to do much the same to the 
Scots in 1327--- occupy the crossings of the Tyne and "require them to fight at a disadvantage, or else 
remain in England, caught in a trap."57 Philip VI tried to accomplish the same objective in 1346, blocking 
the passages of the Somme "so that the King of England and his army could not pass, because he wanted to 
do battle with them at his will, or starve them by the Somme."58 But when Edward III crossed the river at 
Blanchetacque, he achieved his own immediate "positive aim" (securing a clear retreat to Flanders), and 
returned the ball to Philip's court, so that the latter had to accept the tactical offensive or abandon his own 
"positive aim" of eliminating the threat posed by Edward's devastating chevauchées. The result was the 
English victory at Crécy: a model of a successful combination of an offensive strategy with a defensive 
tactical system. 
Such an offensive/defensive strategy, whether pursued through siege, devastation, or simple 
challenge, was one key path to success in late medieval warfare. Although I have focused this paper on 
examples drawn from the Hundred Years War, I think the similar patterns will emerge in other areas--- and 
even in other times when the defensive enjoyed strong superiority both in siege and on the battlefield. The 
problems and solutions arising in such a situation, as I have outlined them, were in large measure familiar to 
Sun Tzu in the fifth century B.C. and to Vegetius in the fourth century A.D., and would have been readily 
grasped by Saxe or Villars in the eighteenth century, or even Clausewitz or Longstreet in the nineteenth. 
Those explorations, though, I will leave to others. 
 
 
 
 
 
56 Cf. Jean de Bueil, Le Jouvencel, 154-5. 
57Jean le Bel, Chronique, 1:55. 
58 Froissart, Oeuvres, 5:2-3.