Historia - RomanArmyTalk · mechanism?2 A still more fundamental question has never been answered ... Roman Infantry Tactics in the Mid ... economic and technological symmetry,

HistoriaZeitschrift für Alte GeschichteRevue d’Histoire AncienneJournal of Ancient HistoryRivista di Storia Antica

Historia Band xx • Heft x • 201x© Franz Steiner Verlag, Stuttgart

ROMAN INFANTRY TACTICS IN THE MID-REPUBLIC: A REASSESSMENT

Abstract: This article explores two questions about the tactical mechanics of the Roman manipular legion. First, what frontages did the Roman legion fi eld in set-piece battle? Given that Hellenistic forces deployed in standardized formations, the length of Hellenistic infantry lines can be used to calculate the opposing Roman formation. This in turn permits consideration of the nature and tactical function of the gaps between the maniples. The paper deduces that Roman legions presented fronts between 320 and 570 meters in fi ve set-piece battles. The range of frontages suggests that modest inter-manipular gaps were maintained even as the heavy infantry lines clashed.

This article offers a reassessment of an old topic: legionary infantry tactics during the age of Roman expansion, in particular the manipular tactics that predominated between the 3rd and 1st centuries BC.1 Despite a keen scholarly interest in Republican tactics dating back to the age of Machiavelli, basic questions still remain concerning Roman tactical dispositions. Students of the Roman army are familiar with one of the most famous (and traditionally fruitless) tactical controversies concerning the manipular legion: did the Romans leave gaps between the maniples in combat, or were they closed by some obscure mechanism?2 A still more fundamental question has never been answered satisfactorily: what was the frontage, or possible frontages, of a legion, and to what extent was that

1 I would like to thank Carlos Noreña, Tom Hendrickson and Laura Pfuntner for reading and comment-ing on early versions of this article. Thanks also to Timothy Winters and Christos Kollias, who took an American School bus on a long detour to allow me to inspect the battlefi eld at Cynoscephalae. The anonymous readers at Historia provided valuable feedback and criticism that led to a vastly improved article. Most of all, my gratitude to my wife Kelsey Mayo and to our little Caroline, for their love and support.

2 A clunky mechanism of laterally counter-marching the rear century to plug the gap is favored by Con-nolly, 1998: 141–142 followed by Daly, 2002: 61–62 et alii, but such a maneuver seems excessively diffi cult to execute under combat conditions. Soltau, 1885: 265–267 and Quesada-Sanz, 2005:7–8 propose having maniples expand laterally into the gaps, with soldiers in the process expanding their frontage from three feet to six feet. This maneuver might be feasible during a lull in combat, but still seems clumsy and time consuming. Delbrück, 1920 {1975}: 273 argues that the intervals were extremely small (more joints than gaps), and were closed automatically as men in the rear ranks pressed forward into them once enemy contact was made. Any large gap was sealed by the timely advance of a century from the principes or triarii.

Historia-Taylor.indd 1 06.07.13 16:53

Kelsey Mayo

PROOF

Kelsey Mayo

Michael J. Taylor2

frontage potentially extended by inter-manipular gaps?3 Answering these questions will greatly illuminate the dynamics of the mid-Republican legion in battle.

Tactical analysis is one facet of ancient military history that has been out of fash-ion for well over a century, after signifi cant interest in German scholarly circles prior to World War I.4 When Frank Adcock delivered his Martins’ Lectures on The Roman Art of War in 1939, the infl uence of German scholarship on manipular tactics had been waning for nearly a generation, and Adcock did not dwell on the question of Manipular-taktik. Since the 1960s, military history, both ancient and otherwise, has fallen mostly into two schools. The fi rst school, sometimes known as the “New Military History,” focuses on the social, political, demographic and economic factors related to warfare, tackling everything from the social makeup of armies and offi cer corps to the cultural impacts of military violence.5 While New Military History has provided many insights, it has one primary drawback: it generally ignores or downplays acts of combat, the very reason why societies muster military forces in the fi rst place. Beginning with the late John Keegan’s 1978 book, Face of Battle, a military-historical school of thought bearing the same name has arisen, focusing on the mechanics of combat at the level of front-line soldiers. Philip Sabin has applied this approach to the Republican Roman legion in his 2000 article “The Face of Roman Battle.”6 The two schools of thought have some overlap. Victor Davis Hanson strongly linked the hoplite “face of battle” to the social and cultural world of the Archaic and Classical polis, while Jon Lendon has recently discussed ancient combat in relation to cultural dynamics, stressing that clas-sical soldiers were motivated by an aggressive and heroic ethos, which was refl ected in their tactical dispositions.7

3 Lendon, 2005: 181–182. Frontages for reconstructed legions vary wildly. Bar Kochba, 1979: 166 suggests each legion at Magnesia had a frontage of 450 meters. Sekunda, 1996: 19 puts the standard frontage of a 4200-man mid-Republican legion at 800 yards (720 meters). Goldsworthy, 1996: 140 suggests that a cohort-based legion could have a frontage of over 1125 meters. Bahmanyar, 2009: 54 estimates legionary frontages of 800–1200 m. I have earlier suggested in a popular publication (Taylor, 2011:12) a range of frontages from 400–850 yards (360–765 meters), although the uncer-tainty led me to reevaluate the problem more closely.

4 The primary benchmarks of late 19th-early 20th century German tradition are Delbrück, 1883, Soltau, 1885, and Schneider, 1893 and the immense corpus of Kromayer and Veith (e. g. Kroymayer, 1905; Kromayer and Veith, 1907). By the time Delbrück published his magisterial Geschichte der Krieg-skunst in Rahmen der politischen Geschichte, intractable controversies remained over the frontage of each soldier (three feet vs. six feet), and the size and purpose of intervals. The diminishing returns in resolving these controversies caused the topic of manipular tactics to be largely abandoned by serious scholarship ever since.

5 For an overview of “New Military History,” see Paret, 1991 and Morillo and Pavkovic, 2006: 37–43. Webster, 1969 and Keppie, 1981 represent the application of New Military History to the Roman army. For a rollicking critique of the current state of ancient military history, see Wheeler, 2011: 54–104.

6 Wheeler, 2001: 169–174 offers a critique of the “Face of Battle” methodology as applied to ancient military studies.

7 Hanson, 1989: passim, Lendon, 2005: 163–211.


Roman Infantry Tactics in the Mid-Republic: A Reassessment 3

Both schools of military history either ignore or minimize the role of tactics. The topic of mid-Republican tactics, however, is not merely an obscure technical question, but rather one that lies at the heart of one of the great problems in Roman history: the need to explain Rome’s rise to pan-Mediterranean dominance in the 3rd and 2nd centuries BC. Unlike European colonial empires from the 16th century onward, which were estab-lished on the basis of overwhelming technological, economic and military superiority, Rome’s Hellenistic opponents (Carthage included) possessed well-organized military institutions, backed by sophisticated state economies. Perhaps most importantly, all Roman warfare was conducted on the basis of basic technological parity, with all sides fi elding an iron-age arsenal of spears, swords and shields, albeit with varying designs. Despite this organizational, economic and technological symmetry, the Roman army was able to triumph repeatedly over formidable rivals in a series of critical wars that would reshape the international dynamic of the Mediterranean basin. While the warfare of the period was often characterized by long and grinding campaigns, as well as plenty of Roman setbacks, it was punctuated by a set of unusually decisive Roman victories in set-piece battles (e. g. Ilipa, Zama, Cynoscephalae, Magnesia and Pydna), where the outcome of entire war hinged upon a single day of fi ghting. The Roman army’s ability to defeat and substantially destroy opposing forces ultimately proved the indispensable prerequisite of Roman expansionism. An examination of the Roman army in its tactical array is therefore central to understanding how this ancient institution shaped the arc of Mediterranean political history.

In exploring mid-Republican tactics, this essay will build conclusions progressing in scope from the level of the individual soldier to the entire legion. First, I propose a hypothesis concerning the space required by Roman soldiers in formation, based on a reassessment of Polybius 18.30, and offer a model for the transition of Roman infantry formations between a defensive close order formation and an offensive open order. Next, I examine fi ve battles fought between Roman and Hellenistic armies. Given that Hellenistic armies utilized doctrinal tactics that are well documented by Polybius and later Hellenistic tactical writers, it is possible to reconstruct Hellenistic battle lines, and in turn to re-imagine opposing Roman infantry frontages. By calculating a range of potential maniple frontages, I note how much of the legionary frontage potentially consisted of the space devoted to inter-manipular gaps. I conclude with a brief discussion of the importance of inter-manipular gaps to the success of the legion on the battlefi eld.

Literary Sources and Roman Tactical Practice

The most reliable source for the mid-Republican army is the contemporary eyewitness Polybius, present in Rome from 167 BC onwards.8 Polybius saw the Roman army in action on multiple occasions; he collaborated with the Roman campaign against Perseus

8 The literature on Polybius is extensive; I have been largely informed by Walbank, 1990, Eckstein, 1995, Champion, 2004, consulting throughout the commentary in Walbank, 1957.


Michael J. Taylor4

and was present as an observer at the siege of Carthage in 146 BC.9 In addition, Poly-bius interviewed veterans of major pitched battles, in particular Gaius Laelius (Scipio Africanus’ chief lieutenant during numerous battles of the 2nd Punic War) and his friend and patron Scipio Aemilianus, who fought as a young man at Pydna.10 Polybius also consulted contemporary military literature: Elizabeth Rawson has argued that he utilized a sort of “fi eld manual” for military tribunes in his composition of Book 6.11

Livy, writing over a century later, was entirely dependent on earlier sources, in-cluding many now-lost passages of Polybius as well as other late-annalistic historians of mixed value.12 Nonetheless, while doubts will always persist about the accuracy of Livy and his even more chronologically removed imperial successors, we do know that these later historians had access to a number of now-lost high quality sources on military affairs from the mid-Republic, including Cato the Elder’s de re militari, Scipio Africanus’ letter to Philip V which described

his actions during the 2nd Punic War, and Scipio Nasica’s eyewitness account of the battle of Pydna.13

The Tactical Space of Roman Soldiers

Scholarly work in the last decade has produced a new model of combat mechanics within the Roman Republican legion. While the individual scholars who have made important contributions to the problem (most notably Adrian Goldsworthy, Philip Sabin, Michael Zhmodikov, Jon Lendon and Fernando Quesada-Sanz) do not agree on all details, a basic consensus has developed. The Roman maniple was not a closely packed, rigid 18th century-style formation, but rather a looser formation that gave individual soldiers signifi cant leeway to break ranks in order to, in the words of the mid-Republican military oath, “retrieve a missile, to pursue and strike an enemy or save a fellow citizen” teli sumendi aut petendi et aut hostis feriendi aut ciuis seruandi causa.14

Nonetheless, it is safe to assume that before the Roman legion engaged in its fl uid style of combat, men were arranged in orderly, roughly rectangular formations. A mani-ple was not a mob. For example, Polybius reports the Romans arrayed for battle against the Gauls in 222 BC with “the tribunes demonstrating to each and all how they should enter battle, both as units and as individual fi ghters” ƲԙƬ ƵƨƪƨнƯƵƷƬ Ґ�ƮƣƤƨƭнƬƲƷƬ Ҝư

9 Polybius as a collaborator in the 3rd Macedonian War: 28.13. Eyewitness to the 3rd Punic War: 38.19; Ammianus Marcellinus 24.2.16. Eckstein, 1995: 280.

10 Gaius Laelius as an informant: Polybius 10.31. Polybius’ close friendship with Scipio Aemilianus: 31.23–25. Aemilianus at Pydna: Plutarch, Life of Aemilius, 22.3–8.

11 Rawson, 1971: 15, 20. Note also the centrality of the tribunes at Pol. 2.33.1. 12 On the formulaic battle narratives in late annalistic historians, see Erdkamp, 2006.13 Scipio Africanus’ letter to Philip: Polybius 10.9.3; Cato’s de re militari: Vegetius 1.8, 1.13, 1.15,

2.3, Frontinus Strat. 3.1.16. Scipio Nasica’s account of Pydna: Polybius 29.14.3, Plutarch Aemilius 18.5. On mid-Republican military memoirs: Canadu, 2011: 122–133.

14 Livy 22.38.4; Lendon, 2005: 179, Quesada-Sanz, 2005: 7. Phang, 2008: 49–60.



ƣƤԃ �ƮƨƤԃƱƧƠƨ ƲҳƬ чƢԙƬƠ ƩƮƨƬӹ ƩƠұ ƩƠƲ› ѳƣрƠƬ јƩнƱƲƮƳư.15 Thus, while maniples in combat might subsequently bunch up or stretch out in the inevitable chaos of combat, it is possible to consider the pre-combat arrangement of soldiers, and the depths and frontages of their maniples.

Polybius describes the Roman infantry dispositions as follows (18.30.6–8):

ѸƱƲƠƬƲƠƨ ƫҭƬ ƮҕƬ їƬ ƲƯƨƱұ �ƮƱұ ƫƤƲҫ ƲԙƬ ҈�ƪƷƬ ƩƠұ ԕƷƫƠԃƮƨ· ƲӸư ƫнƵƦư ƣ› ƠҏƲƮԃư ƩƠƲ› ыƬƣƯƠ ƲүƬ ƩрƬƦƱƨƬ ƪƠƫơƠƬƮхƱƦư ƣƨҫ Ʋҳ ƲԚ ƫҭƬ ƧƳƯƤԚ ƱƩо�ƤƨƬ Ʋҳ ƱԙƫƠ, ƱƳƫƫƤƲƠƲƨƧƤƫоƬƮƳư ƠѳƤұ �Ưҳư ƲҳƬ ƲӸư �ƪƦƢӸư ƩƠƨƯфƬ, Ʋӹ ƫƠƵƠрƯӬ ƣ› їƩ ƩƠƲƠƴƮƯӮư ƩƠұ ƣƨƠƨƯоƱƤƷư �ƮƨƤԃƱƧƠƨ ƲүƬ ƫнƵƦƬ, �ƯƮƴƠƬҭư ҈Ʋƨ ƵнƪƠƱƫƠ ƩƠұ ƣƨнƱƲƠƱƨƬ чƪƪпƪƷƬ ћƵƤƨƬ ƣƤпƱƤƨ ƲƮҵư ыƬƣƯƠư їƪнƵƨƱƲƮƬ ƲƯƤԃư �фƣƠư ƩƠƲ› ї�ƨƱƲнƲƦƬ ƩƠұ ƩƠƲҫ �ƠƯƠƱƲнƲƦƬ, Ƥѳ ƫоƪƪƮƳƱƨƬ ƤҏƵƯƦƱƲƤԃƬ �Ưҳư Ʋҳ ƣоƮƬ.

Each Roman with his equipment also occupies three feet. But in their manner of fi ghting each man undertakes movement on his own, protecting his body with his long shield, parrying a blow, and fi ghting hand to hand with the cut and thrust of his sword. They therefore clearly require a space and fl exibility between each other, so that each soldier must have three feet from the man to their fl ank and rear, if they are to be effective.

Here it is important to differentiate between “tactical space,” the total amount of space a soldier has before bumping into his comrades on the left and right, and “fi le width,” the amount of space a soldier has from the right shoulder of the man on his left to his own right shoulder. This passage is usually interpreted to suggest that the fi le width of each Roman soldier was six feet (1.8 meters): the three feet the soldier physically occupies plus the three-foot gap to the man on his right and another three feet to the left.16 This would give the Roman soldier a tactical space of nine feet. Such spacing is undeniably too generous, as it would leave the Roman infantryman painfully exposed while dramatically reducing the weapons density of the front line.17 However, this does not mean the passage should be ignored in favor of the spacing indicated by Vegetius (3.14), who assigns a mere three feet to each Roman soldier. From a source criticism perspective, to prefer the Late Imperial Vegetius over the contemporary Polybius is a dubious choice.18 More materially, Vegetius’ spacing simply does not provide suffi cient room to fi ght.

15 Polybius 2.33.1. 16 E. g. Walbank, 1957: 588–589.17 Delbrück, 1975 {1920}: 406–410, Daly, 2002: 160, Goldsworthy, 1996: 171. 18 It should also be noted that while Vegetius 3.14–15 makes reference to hastati and principes, none

of the formations he describes bears any resemblance to mid-Republican tactics: he reports forma-tions of up to 10,000 men arrayed into huge blocks, and makes no mention of maniples, the triplex acies or legions and alae. I do not believe it is correct to assume that this section utilizes a Repub-lican source (pace, Goldsworthy, 1996: 179). More likely this passage represents a typical Vegetian amalgam of sources and historic periods, a hypothetical exercise that is unrelated to any historical tactical disposition.


Michael J. Taylor6

The Roman soldier required signifi cant space to wield his sword, if only to prevent him from accidentally slicing the comrade next to him. Archaeological developments in Spain over the last fi fteen years have identifi ed the gladius hispaniensis, and revealed that it was in fact quite long for an ancient infantry sword.19 Average blade length, not counting the tang, was 65 centimeters (25 inches), substantially longer than Greek and Macedonian blades.20 The length of blade confi rms testimony in both Polybius and Livy that indicates the essential slashing function of the sword.21 Slashing motions with a 62–69 cm blade would have required an open spacing, whereas Vegetius’s spacing of three feet would facilitate only cramped and ineffective stabbing motions.22

It seems that the correct reading of Polybius refers to a tactical space of six feet, rather than a fi le width, with the former defi ned as the space between a soldier’s comrades on the right and left, and the latter being the space each soldier occupied calculated from right shoulder to right shoulder.23 Polybius does not distinguish between the two, partly because in his discussion of Macedonian soldiers in close order, fi le width and tactical space are identical. The Macedonian only has the space he physically occupies along with his arms and equipment, and brushes up against the men on either side.24 The Roman soldier has double the tactical space of a Macedonian soldier, some six feet to operate in compared to three feet, but the actual “fi le width,” from right shoulder to right shoulder, would in fact be four and a half feet per soldier, given that some of the six feet of frontage is shared between adjacent soldiers.25 This is a plausible space in which to engage in vigorous swordplay, but not so wide as to make individual Roman soldiers excessively spaced and isolated on the battlefi eld.

A 4.5 foot fi le width would have been quite easy for soldiers themselves to meas-ure. Modern soldiers in the US Army conducting drill and ceremony obtain a “Normal Interval” of just under 4.5 feet simply by holding out their right arm until they touch the left shoulder of the soldier next to them, and this expedient was available to their ancient counterparts.26 Indeed, this sort of measurement may be exactly what Polybius

19 Quesada-Sanz, 1997: 256; 2005: 6. Bishop and Coulston, 2006: 55–56. 20 Snodgrass, 1967: 84–85, 119, illustrations no. 50–52. Greek swords generally have a total length of

just under 55 cm, with blades of around 45 cm, refl ecting their use as secondary weapons in compact formations.

21 Bishop and Coulston, 2006: 56. The Pydna monument at the Delphi museum (c. 160) depicts a Ro-man soldier making a broad overhead slashing movement with his sword.

22 Gladius hispaniensis: Quesada-Sanz, 2005: 6. Kromayer, 1905: 11–13 vigorously argues that three feet was insuffi cient spacing, part of an ongoing, and often testy, exchange with Hans Delbrück.

23 Sage, 2008: 85–86 argues that Polybius’ six feet should be read from the left shoulder of the soldier on his right to the right shoulder of the soldier on his left, and suggests a roughly two foot interval between soldiers.

24 Polybius 18.29.1–5.25 Polybius states that the Roman soldier occupies a physical three feet of space (for shield, and the

part of the body not covered by the shield), in the center of his six feet of frontage. This implies 1.5 feet of empty space on either side, for a fi le width of 4.5 feet. Throughout I will convert a foot to .3 meters, admitting that it is unclear which ancient foot Polybius is using.

26 US Army Training Circular (TC) 3.21.5 (Drill and Ceremonies), Figure 6.2.



has in mind when he describes ƲƯƤԃư �фƣƠư…ƩƠƲҫ �ƠƯƠƱƲнƲƦƬ, as a Greek would measure three feet (a half orguia) from the fi ngertips of his outstretched arm to his nose, so that Polybius’ “three feet on either side” (six feet, a full orguia) would include the space the soldier himself physically occupies.27

A Roman soldier’s shield ultimately defi ned the dimensions of his tactical space, and here it is perhaps no coincidence that a Roman scutum was just over two feet wide, or approximately half a fi le-width. Polybius (6.23.4) reports that the Roman scutum was 2.5 feet (.75 m) lengthwise, although this likely refers to the span of the convex face of the shield, making the actual width c. 65–70cm.28 Our only surviving Republican-era shield, found in the Fayum at Kasr el-Harit, and dating to the Late Republic, has a width of .635m.29 Roman shield widths would have varied, given that Roman militiamen sup-plied their own equipment. Nonetheless, the Romans did seem to have a general sense of a “standard” shield, so that Scipio Aemilianus could admonish a soldier for having amplius eum scutum iusto ferre.30

We therefore have a simple mechanism by which Roman soldiers measured their own frontage: in the early phases of battle, characterized by missile exchange, soldiers adopted a close order formation with shields touching or nearly touching. As the battle moved into a phase of hand-to-hand combat, the formation opened by fl exing forward, so that every legionary had a fi le width roughly double a shield-width, approximately 4.5 feet (1.35m), the fi gure used in my calculations.

Close Order and Open Order Formations

Several passages describe the transition from close order formations to open ones: Livy (28.2.7–9) describes a shower of Celtiberian javelins during the 2nd Punic War which “the Romans, closing together according to custom, received with their shield wall” romani conferti, ut solent, densatis excepissent scutis. Once they had received the missile barrage and began to advance over rough terrain, the Romans fl exed into a more open formation, so that “they opened their ranks and clashed singly or in pairs, resembling matched gladiators” ordines dirimebant et singuli binique uelut cum paribus conserere pugnam cogebantur.

27 An orguia is prominently featured on the Salamis Metrological Relief, on display in the Piraeus Archaeological Museum; Dekoulakou-Sideris, 1990: 446–447.

28 Treloar, 1971: 5. 29 Kimmig, 1940, although the shield is identifi ed incorrectly as Celtic. This shield may be a Roman

model used by Ptolemaic soldiers (or Roman mercenaries in Ptolemaic service). An early imperial auxiliary shield from Doncaster, while differing in construction from a Republican scutum, also has a width of .64 m (Buckland, 1978: 256), almost identical to the Fayum scutum. Both Polybius and the Fayum scutum are similar to the images of Republican scuta on the Pydna monument and the Louvre “Ahenobarbus” Relief. See also Sekunda, 2006: 80–83, who emphasizes the Fayum shield is of Roman design.

30 Livy Per. 57.


Michael J. Taylor8

Surrounded by Macedonian skirmishers during the 3rd Macedonian War, the com-manding tribune of a Roman foraging party “formed the soldiers into a circle, so that they might defend themselves with a shield wall from the hail of arrows and darts” in orbem milites coegisset, ut densatis scutis ab ictu sagittarum et iaculorum sese tueren-tur – note the repetition of the phrase densatis scutis. In this initial defensive formation, the soldiers lacked suffi cient space to effectively wield their weapons. They eventually attempted to open their ranks by fl exing forward: ordines procursando soluissent.31 We see a similar trend in an urban environment: during the siege of Sparta in 195 BC, Ro-man soldiers formed a close order testudo in response to missile fi re.32 However, they soon sought tactical space to wield their weapons, taking advantage of a patentiorem uiam to transition to the offensive.33

The need for Roman soldiers to lock shields when on the defensive, particularly in response to missile threats, may also explain one of the most puzzling passages in Polybius, one commonly bracketed as corrupt. Polybius (15.13.1) reports that the Ro-man hastati fought at Zama “using neither spears nor swords” ƫү ƣфƯƠƱƨ ƫƦƣҭ ƭрƴƤƱƨ ƵƯӸƱƧƠƨ.34 What Polybius may in fact describe is the Romans’ close order formation in response to the missile threat coming from Hannibal’s Balearic slingers and other light infantry in the Carthaginian fi rst line. However, the hastati then struggled to fl ex forward out of their defensive formation to obtain the space they needed to effectively wield their swords in an open order, and so the fi ghting for a while involved Romans in close order shoving forward with their shoulders against interlocked shields.35

Transition to an open order formation may have been as simple as every other man in the front ranks stepping forward until they achieved appropriate intervals. (Likewise, closing the ranks might involve soldiers in alternating rear ranks stepping forward between the two men in front).36 If this maneuver were conducted by fi les, the entire formation would double its depth as it transitioned into open order, although in the press of combat it is possible that only the fi rst few ranks would do so. A fl uid open order

31 Livy 42.65.7–9, Zhmodikov, 2000: 74. 32 Livy 34.39.6–8.33 Cf. Caesar, BG 2.25.2 for a transition into the offensive: manipulos laxare iussit, quo facilius gladiis

uti possent and Tacitus, Hist. 3.17 for a defensive formation densis ordinibus.34 For an overview of criticism of the passage and various interpretations, see Walbank, 1957: 459. Livy

seems to have read the passage and interpreted that the Romans fought “striking with shoulders and shield bosses” ala deinde et umbonibus pulsantes. Polybius is no doubt in error if he characterizes all hand-to-hand fi ghting during the battle in this manner. The heavy casualties the Romans infl icted on the fi rst two lines of Carthaginians suggests that they did indeed fi nd suffi cient tactical space to wield their weapons with deadly effect.

35 For a similar case of close order othismos with locked shields, see Livy 34.46.10–11, as Roman soldiers struggled to egress out of a narrow gate, and were for a while unable to open their forma-tion.

36 Sabin, 2001: 10, Daly, 2002: 61 and Judson, 1888: 43, although all suggest movement from a three foot spacing to a six foot spacing. Cf. US Army TC 3.21.5, (Drill and Ceremonies) Paragraph 7–7, “Opening and Closing Ranks,” for a similar maneuver used by modern troops on parade.



could also be achieved in melee combat with the most daring soldiers dashing forward to form a loose skirmish line, still the preferred technique of Pompeian troops in Spain during the Late Republic.37 In both cases, the frontage of the maniple remained the width of the original close order shield wall.

Number of Ranks in Roman Formations

Cato the Elder writes in his de re militari (Jordan 9.1) that pedites quattuor agminibus equites duobus antibus ducas. The quattuor agmines may well be the four columns of velites, hastati, principes and triarii, although the pairing with the term antes (a word also applied to rows of vines) implies ranks of soldiers within a formation. If so, Cato may envision a tactical system based on fi les of 4/8 in close/open order.38 Livy (44.9.6) reports a testudo four-men deep in 169 BC. It is not impossible that the four man guard details (ƴƳƪƠƩƤԃoƬ) described by Polybius (6.33.7) correspond to a close-order fi le. Looking beyond the mid-Republic, data concerning the depth of Roman soldiers in for-mation in is rare, scattered chronologically, and from sources of varying quality. Table 1 collects references spanning from the mid-Republic into the Late Empire:

Table 1: Depth of Roman Soldiers in Formation Source Depth Formation Type Date of ActionRepublican Period Cato, de re militari 4 Unknown n/aLivy 44.9.6 4 Testudo 169 BCFrontinus 2.3.22 10 Combat 48 BCPlutarch, Antony 45.2 3 Testudo 36 BCImperial Period Josephus BJ 2.172 3 Riot Control Cordon 26–36 ADJosephus BJ 5.131 3 Defensive perimeter 70 ADJosephus BJ 3.124 6 Marching column 60s ADTrajan’s Column 4 Testudo 100s AD39

Arrian Ectaxis, 16–17 8 phalanx 135 ADColumn of M. Aurelius 3 Testudo 170s AD40

Vegetius 1.26 4 Training drill n/aVegetius 3.14–15 3,6,9 Combat n/a

37 Caesar, BC, 1.44.1–2: Genus erat pugnae militum illorum, ut magno impetu primo procurrerent, au-dacter locum caperent, ordines suos non magno opere servarent, rari dispersique pugnarent. Kromayer, 1905: 15–17 proposes a similar method of developing a battle line out of a close order formation.

38 Wheeler, 2004: 160. Wheeler suggests that Cato himself may be reliant on a Greek tactica, possibly by none other than Polybius.

39 Photo in Settis et al., 1988: 376.40 Photo in Coarelli, 2008: 220–221.


Michael J. Taylor10

While the evidence is hardly conclusive, close order formations three or four men deep appear with the greatest frequency, which would then presumably transition into open order formations six or eight deep. The deepest attested (open order?) formation is Pompey’s ten ranks at Pharsalus (Frontinus 2.3.22), although Polybius reports unusually deep mid-Republican formations at Tunis and particularly at Cannae, where the depth of maniples is said to be many times the width of their front.41

In the next section I will attempt to ascertain the size of legionary frontages, and from this deduce the width of inter-manipular gaps necessary to maintain those forma-tions. Given the uncertainty regarding the exact depth of maniples in any engagement, I will calculate maniple frontage based on a range of possibilities, namely formations in close/open order 3/6 deep, 4/8 deep, 5/10 deep, and so on (see Table 2). Fortunately, it will not be necessary to plug in endless variables, as a point will quickly arrive where the maniples could not be made deeper without making the inter-manipular gaps larger than the frontage of the maniple itself. I will, however, exclude formation depths of one and two ranks deep in close order, which are not attested in any historical source.42

Such formations would be too shallow to be tactically effective, as the death of a few soldiers would quickly dissolve the integrity of the entire line.

Case Studies

To determine the overall frontage of a Roman legion, I will examine Roman dispositions in battle against Hellenistic enemies whose strength and tactical disposition are relatively well attested in ancient sources. This project supposes that Roman commanders actively attempted to match the frontage of the opposing force.43 All ancient armies had reason to be concerned that the opposing infantry line would extend its wings and turn one or both fl anks. The Athenians and their allies at Nemea in 394 BC engaged in lengthy counsels to determine the appropriate depth of their forces to ensure that their line was of suffi cient length to prevent a Spartan envelopment.44 Caesar, badly outnumbered while fi ghting in Africa, was forced to extend his line into a simplex acies when faced

41 Polybius reports that the legions at Tunis in 255 BC were formed ƲүƬ ƣҭ Ʊхƫ�ƠƱƠƬ ƲнƭƨƬ ơƯƠƵƳƲоƯƠƬ ƫҭƬ ѥ �ƯфƱƧƤƬ, ơƠƧƳƲоƯƠƬ (1.33.10), while at Cannae in 216 the maniples were �ƳƩƬƮƲоƯƠư ѥ �ƯфƱƧƤƬ Ʋҫ ƱƦƫƤрƠư ƩƠƧƨƱƲнƬƷƬ, ƩƠұ �ƮƨԙƬ �ƮƪƪƠ�ƪнƱƨƮƬ Ʋҳ ơнƧƮư їƬ ƲƠԃư Ʊ�ƤрƯƠƨư ƲƮԏ ƫƤƲц�ƮƳ (1.113.3–4).

42 The only reference to ancient formations two men deep come from a fantastic passage in Xenophon, describing a battle between Persians arrayed two deep, and Egyptians arrayed 100 deep, which should not be taken for evidence of a historical formation (Xenophon, Cyropaedia, 6.3.21–7.1.34; see Wheeler in Sabin et al., 2007: 210).

43 On the symmetry between opposing armies in the ancient world, see Sabin et al., 2007: 405. N.B. Onasander 29.3, that good commanders should base their deployment off the initial deployment of opposing forces.

44 Xenophon, Hellenica 4.2.13: ҈�Ʒư ƫү ƪрƠƬ ơƠƧƤрƠư Ʋҫư ƴнƪƠƢƢƠư �ƮƨƮхƫƤƬƠƨ ƠѴ �фƪƤƨư ƩхƩƪƷƱƨƬ ƲƮԃư �ƮƪƤƫрƮƨư �ƠƯоƵƮƨƤƬ. Cf. Pritchett, 1985: 74.



with a Pompeian assault.45 Fighting against a numerically superior Parthian army in the 3rd century AD, Herodian (4.15.1) reports “the Romans no longer deployed their bat-tle line in depth, but continuously extended it lengthwise to avoid encirclement” ƮѴ ƣҭ ԕƷƫƠԃƮƨ ƮҏƩоƲƨ Ʋҫư ƴнƪƠƢƢƠư їư ơнƧƮư ƱƳƬрƱƲƠƱƠƬ, їư ƫӸƩƮư ƣ› їƩƲƤрƬƮƬƲƤư чƤұ Ʋҳ ƩƳƩƪƮхƫƤƬƮƬ їƬƤ�фƣƨƥƮƬ. Perhaps the best example of mutual extension of battle lines from the mid-Republic comes from the battle of Zama, where both Scipio and Hannibal simultaneously lengthened their lines before the fi nal infantry clash.46 While mid-Republican commanders would have felt obliged to extend their line to match that of their enemy for the sake of fl ank security, they seldom sought to extend their own lines past that of their opponents. This stemmed from a cautious impulse also common to many ancient commanders, given that overextended wings were diffi cult to control, and excessively thin lines were at risk for breakthrough by the enemy.47 Roman generals on the whole preferred to initiate fl anking maneuvers either with a picked force stationed outside of the battle line (as at Corinth and Aquae Sextiae), or through the deployment of one of the reserve lines (as at Cynoscephalae).48

According to Polybius, each Macedonian soldier required three feet (.9m), for himself and his weapons.49 Despite various attempts to suggest a narrower frontage for a phalangite, I believe that .9m is indeed the correct estimate for phalangite fi le-width/frontage.50 Representational evidence, particularly the Shield Monument at Veria, sug-gests that the Macedonian shield was approximately .70–.75 meters wide.51 The fi ve sarissai projecting from each fi le would need room as well, as each sarissa shaft had a diameter of circa .04 meters.52 Therefore, .9 m for the fi le width of a phalanx is in fact

45 Caesar, African War 13, 17. interim Caesar aciem derigit simplicem ut poterat propter paucitatem (13)….Caesar interim consilio hostium cognito iubet aciem in longitudinem quam maximam porrigi et alternis conversis cohortibus ut una post, altera ante signa tenderet (17).

46 Hannibal lengthens lines by forcing retreating Carthaginian levies to take positions on the fl anks: Polybius 15.13.10. Scipio lengthens his line: Polybius 15.14.3. Cf. Lazerby, 1978: 224–225, Scullard 1930: 248.

47 Sabin et al., 2007: 405.48 Corinth: Pausanias, 7.16.3; Aquae Sextiae: Plutarch, Marius 20.4, 21.1; Cynoscephalae: Polybius

18.26.1–4.49 Polybius 18.29.2, cf. Asclepiodotus 4.1–3.50 Delbrück, 1975{1920}: 404 suspected that .9m was actually too generous a space for a phalangite,

and that their spacing in closed order was perhaps 1.5–2 feet, based in part on an experiment con-ducted in a Berlin gymnasium. His students, however, while equipped with long shafts, did not have shields. Pritchett (1971, 152–154) more cautiously suggests lowering the estimate to .8 meters, based on the width of the Getty Museum shield, although this gives no room for the sarissa shafts!

51 Veria Monument: Markle, 1999: 246–250; The Getty Museum Shield (80.AC.60) has a width of 81.4 cm, at the upper end of the spectrum of Macedonian shield diameter. A shield monument in the Athenian Agora, unearthed in 2010, depicts the life-sized equipment taken from a defeated enemy, spoils which the excavator identifi es as Macedonian (Camp, 2010). The shield here is .69 m in di-ameter, similar to those of the Veria Monument. My thanks to John Camp for allowing me to view the monument in situ while a student at the American School in Athens.

52 Sarissa shaft diameter: Markle, 1977: 324.


Michael J. Taylor12

somewhat conservative. File widths of .9 meters would produce a tight formation in which shields, elbows and sarissa shafts pressed together, warranting the terms pyknosis and synaspismos used to describe it.53 A smaller Macedonian shield, circa .6–.66m was also in use, and is generally identifi ed as the target used by elite peltasts.54 As such, the frontage estimate of Hellenistic peltasts (caetri, argyaspides, etc.) should be reduced by 10 cm to account for their smaller shields, to .8m.

Polybius assumes that a Macedonian phalanx has a standard depth of 16, but notes the existence of double or even quadruple phalanxes, 32 to 64 men deep (12.20.10).55 Asclepiodotus (2.7) likewise places the ideal phalanx depth at sixteen men, which can be doubled to 32. Asclepiodotus states that light troops were generally disposed in a depth of eight (6.2), which seems to have been standard (based on the hoplite tradition), and I will generally use this in my calculations for Hellenistic light troops.56 Based on the tactical doctrine provided by Polybius and Asclepiodotus, it is possible to turn refer-ences to troop strength in battle narratives into frontages.57

In the attempt to tease out Roman frontages from surviving battle narratives, it is necessary to offer my own reconstruction of various battles for which suffi cient evidence survives. In each instance, I will offer hypotheses to fi ll in the gray areas of the textual evidence. There is substantial margin of error in the reconstruction of any single battle, based on either the ambiguities in the texts or inevitable errors in my own historical judgment. However, the case studies taken in aggregate suggest a plausible range in the frontage of Roman legions as well as a discernable pattern in the size of implied inter-manipular gaps.

Heraclea (280 BC): Pyrrhus landed in Italy with a heavy phalanx of 20,000, as well as 3000 elite troops in his vanguard, likely hypaspists/peltasts.58 He subsequently added troops from the Tarentine muster, and confronted the Roman consular army under Valerius Laevinus at the Siris River in 280 BC. Pyrrhus deployed his Tarentine infantry in a vanguard to secure the riverbank. After a sharp cavalry action, the legions forced a crossing, easily disrupting the Tarentine screen. Pyrrhus deployed his main phalanx (presumably with his 3000 “hypaspists”) and elephants, and succeeded in breaking the legions after a prolonged clash of the main infantry lines.59

53 Asclepiodotus uses the term synaspismos to describe a specifi c spacing of .45 meters. Polybius and those following him use the term more casually, usually in reference to the .9 m spacing. See Pritchett, 1971: 151–153.

54 Hammond, 1996: 365–367; Sekunda, 2011: 461–462.55 Arrian reports Alexander the Great deployed a phalanx 120 men deep, when pinned in extremely

narrow terrain (Anabasis 1.6.1).56 For eight as a standard depth of Greek hoplite troops, see Pritchett, 1971: 135 (Table 4).57 I acknowledge here that most references to strength in ancient sources presumably refer to “paper”

strength, and that most military units are inevitably understrength during operations. I will assume, however, that both sides were understrength in roughly equal proportion.

58 Plutarch Pyrrhus, 15.1. While Pyrrhus’ force was badly battered by storms, most of his troops even-tually landed in Tarentum.

59 Battle of Heraclea: Plutarch Pyrrhus, 16–17, using Hieronymus of Cardia as a source, among others.



If the 23,000 heavy infantry maintained a depth of 16 in close order, it would have presented a front of 1275 meters. We must assume that Laevinus commanded a standard consular army with two standard-strength legions (4200) and accompanying alae.60 This would put the frontage of each of Laevinus’ legions and alae at c. 320 meters. With a depth of 3/6 in close/open order, his maniples would require only small gaps of around fi ve meters apart. At a depth of 4/8 in close/open order, gaps of roughly 12 meters would be necessary to maintain such a front. At a depth of 5/10 in close/open order, gaps of roughly 15 meters would be necessary, although any depth beyond that would not be feasible, as the gaps would be larger than the maniples themselves.

Cynoscephalae (197 BC): At Cynoscephalae, both armies were roughly equal in size, at c. 26,000 troops. Philip V deployed a phalanx of 16,000, in addition to 2000 peltasts, 2000 Thracians, 2000 Illyrians and 1500 mercenaries.61 Flamininus’ two le-gions were c. 4200 strong, a fact that is nowhere explicitly stated, but readily deduced. Firstly, Plutarch reports Flamininus had c. 26,000 troops, from which 6400 Aitolians, 1200 Athamanians and 800 Cretans/Apollonians must be subtracted.62 This gives a rough estimate of 17,500 Roman troops, or 4,400 a legion/ala, counting cavalry. The detachment previously reported by Livy (32.11.7) at the Aous Pass consisted of 4000 infantry and 300 cavalry, and is surely a single legion. Thus Flamininus’ legions were standard strength of 4000–4200 infantry.63

Polybius reports that after sharp initial skirmishing, Flamininus drew up his legions while Philip V hastily deployed an attack against the legion and ala on the Roman left. Polybius claims that Philip had the right wing of his phalanx (8000 men) and 2000 peltasts.64

60 Pyrrhus had 23,000 infantry, 3000 cavalry, 2500 lights, and an unknown number of Tarentine militia. Justin (18.1.5) reports that Pyrrhus was numerically inferior. I suspect this is only true if one counts the second Roman army then operating in Southern Italy under the pro-consul Aemilius Barbula, giving the Romans strategic, if not tactical superiority over Pyrrhus.

61 Livy 33.4.3–662 Aitolian strength: Plutarch, Flamininus 7.3. Remaining allies: Livy 33.3.9–10 (Livy is certainly

wrong on Aitolian strength, placing it at 600 infantry, rather than 6000). 63 The hastati legionis in Livy 33.1.2 are numbered at 2000 men, leading various scholars (Walbank,

1957: ii. 585; Sekunda, 1996: 36) to conclude that Flamininus’ legions were super-strength, with 200 hastati per maniple. However, the hastati legionis may instead refer to both Roman and allied hastati combined from the legion and its allied wing, c. 2400 if each contained 4000–4200 men.

64 Polybius subsequently says that he committed to battle “with the greater part of the phalanx still on the way” (ћƲƨ ƲԙƬ �ƪƤрƱƲƷƬ ƫƤƯԙƬ ƲӸư ƴнƪƠƢƢƮư ƩƠƲҫ �ƮƯƤрƠƬ ҇ƬƲƷƬ), although it is unclear exactly what he means by this phrase. Polybius elsewhere uses the term pleiston meros quite casually (e. g. 15.13.6), and as Arthur Eckstein notes, Polybius structures his entire narrative to emphasize Philip’s haste and impetuousness (Eckstein, 1995:187–190). It should be noted that while Philip likely began deploying his phalanx while the rear fi les of his right wing were still catching up, a lull seems to have taken place that allowed Philip to organize his troops, and on the Roman side permitted a substantial force of light infantry to withdraw through the inter-manipular gaps to the rear. Presumably by the time the right wing of the phalanx charged, it had fully formed.


Michael J. Taylor14

Polybius subsequently reports that Philip doubled the depth of the peltasts and phalanx as he rushed them into position. Some have taken this to mean he assigned a depth of 32, given that the standard depth of a phalanx was 16. I am inclined to believe that Philip in fact merely transitioned his phalanx from a marching formation eight deep to a standard fi ghting formation 16 deep, one no different from the phalanx Polybius describes in his digression on the merits of the phalanx versus the legion which follows immediately after his narrative of the battle.65

Philip’s light troops in his right wing consisted of 2000 Illyrians and 1500 Greek mercenaries. His Thracians, explicitly excluded by Polybius from the light troops in-volved in the initial skirmish, likely comprised the Macedonian rearguard, and never seem to have been involved in the battle, although they are listed amongst the survivors rallied by Philip.66 In my calculations I will assume the mercenaries and Illyrians were grouped in a “hoplite” formation with an average depth of 8 and a spacing of .9m.67

From the disposition of Philip’s right, we can roughly calculate the frontage of Flamininus’ left, which consisted of a single legion, its paired ala and an unspecifi ed number of light troops.

Illyrians: 225 m Mercenaries: 170 m Phalanx (8000): 450 m Peltasts 100 m Total: 945 m

How many allied light infantry did Flamininus have on his left? We know that he had 8000 altogether, not counting his velites. Roughly 3000 auxiliary light infantry had been part of the skirmishers, and had been received through Flamininus’ line and into his rear.68 The remaining Aitolians did not play a major part in the battle, and according to Polybius’ uncharitable but not necessarily inaccurate report, many slipped away to pil-lage the Macedonian camp.69 Most of the Aitolians were possibly among the otherwise unattested Roman camp guard, a chore that would require roughly 2000 troops, and one which was often tasked to non-Italian auxiliary infantry.70 The eight hundred archers

65 Hammond, 1984 initially supports the idea that the Macedonians phalanx had a depth of 32 men. Hammond and Walbank, 1988: 441, however, place the depth at 16, representing the triumph of Walbank’s view over Hammond’s. Cf. Walbank, 1957: ii 583, Barnes, 2005: 357, Sage, 2008: 173.

66 Thracians excluded from Philip’s right: Polybius 18.22.2. Rallied by Philip after battle: Polybius 18.26.9.

67 Illyrians as a rule fought in a phalanx-style formation in the manner of Greek hoplites (Vegetius 2.2).68 Polybius 18.21.5, Livy 33.7.9. 2000 of these are identifi ed as mostly Aitolians. The fi rst 1000 of

the light infantry were not Roman, given that Polybius identifi es them as ƤғƥƷƬƮƨ, rather than ƢƯƮƱƴƮƫнƵƮƨ, his usual terms for Roman velites. It certainly made more sense to detach Greek infantry rather than velites, to maintain the unit integrity of the legions. Also, in sending forth Apol-lonians or Aitolians, he would have been dispatching men more likely to be familiar with the terrain.

69 Polybius 18.27.4 cf. Eckstein, 1987: 288, n.79.70 2000 strong camp guard (at Magnesia): Livy 37.39.12.



were likely interspersed among the infantry, rather than fi ghting as a single battalion. The number of light troops deployed in Flamininus’ left wing was therefore roughly 2000. These would have a front of approximately 225 meters. This meant that the Ro-man legionary line on the left wing, one ala and one legion, covered approximately 720 meters, or 360 for a single legion. If the maniples maintained a depth of 3/6 in close/open order, they would require gaps of roughly nine meters. If they maintained a depth of 4/8 in close/open order, the gaps would need to be 16 meters to maintain this front. A close/ open order depth of 5/10 or more would not be possible, given that the gaps would by necessity be larger than the maniple frontages.

Magnesia (190 BC): The battle of Magnesia was one of the great lopsided victories in ancient history, as nearly 30,000 Roman and Attalid troops crushed the 72,000-strong army of Antiochus III. The Seleucid infantry line was anchored by its main phalanx, 16,000 men strong, 32 men deep, divided into ten divisions. There were two elephants in each interval, with supporting light troops. I will place the total front-age of the phalanx and elephants at 550 meters (450 for the phalangites themselves, with 100 meters estimated for the elephants and supporting light troops).71 On either side of the phalanx were two divisions of Gallic infantry, 1500 men each. While I have generally assigned light infantry a depth of eight, Antiochus III arrayed his forces with increased depth, and it makes sense he would compliment his double-deep phalanx with extra-deep ranks of supporting light infantry. I will therefore hypothesize a depth of 12 to the Galatian infantry. A depth of 12 provides a neat coincidence, as it would suggest that the remaining 4700 infantry (2000 Cappadocians and 2700 mixti) between the Galatians and the left division of Seleucid cavalry had a front of 350 meters, almost equal to the frontage of the 3000 Achaean and Attalid light infantry opposite them, if these maintained a standard depth of eight.

Antiochus’ right wing presents a puzzle. Livy suggests that to the left of the main phalanx and its screen of 1500 Galatians was posted fi rst 3000 cataphracts, then 1000 cavalrymen of the Agema, and then in the infantry of the Silver Shields, which if correct would provide a rare instance of a heavy infantry unit being placed on the extreme fl ank of a cavalry unit. It would also be a major deviation from Hellenistic tactics, as since Alexander the elite infantry guard unit had traditionally been posted to the immediate right of the main phalanx.72

However, Polybius’ fi erce derision of Zeno’s account of the Battle of Panion (c. 200 BC) provides some insight into what Antiochus may have been doing with his right wing. Polybius’ criticism is profoundly confused in its own right, but he rails against Zeno for claiming that Antiochus here placed a brigade of Tarantine cavalry, along with his own “companion” cavalry in front of the main phalanx.73 Despite Polybius’ uncharitable cri-

71 Bar Kochba, 1979: 167 gives each elephant ten meters; fi ve meters per elephant seems more than suffi cient to me.

72 On the conservatism of Hellenistic tactics: Lendon, 2005: 143–145.73 Polybius 16.18.7–10: ƫƤƲҫ ƣҭ ƲƠԏƲн ƴƦƱƨ Ʋҫ ƧƦƯрƠ �ƯƮƲнƭƠƨ ƲӸư ƴнƪƠƢƢƮư їƬ ƣƨƠƱƲпƫƠƲƨ ƩƠұ

ƲƮҵư ƫƤƲ› яƬƲƨ�нƲƯƮƳ ƚƠƯƠƬƲрƬƮƳư, Ʋҫ ƣҭ ƫƤƲƠƭҵ ƲԙƬ ƧƦƯрƷƬ �ƪƦƯԙƱƠƨ ƲƮԃư ƲƮƭфƲƠƨư ƩƠұ


Michael J. Taylor16

tique, it is likely Zeno was correct, and that Antiochus was experimenting with cavalry charges followed up by infantry assaults.

It is quite possible that Antiochus effected a similar arrangement at Magnesia, but Livy (or his source, most likely Polybius himself) has simply become confused, plac-ing the Silver Shields on the fl ank of the cavalry. Rather, I suspect Antiochus stretched out the unit (Livy claims it deployed cornu producto) to provide a tactical base for his heavy cavalry deployed to its front. This way, the king could focus his cavalry charge against the legions without worrying about opening a gap in his own front, while the Silver Shields could also be used as a mopping up force after the cavalry charge had shattered the legions.

The cornu productum did not have to be deep, given that it stood behind over 4000 heavy cavalry. In fact, it is plausible to assume that for this purpose a depth of eight men would have been entirely adequate, producing a frontage of approximately 1000 meters assuming the Silver Shields maintained a strength of 10,000.74 If the 16 elephants on the left wing were placed in support in a manner similar to those in the main phalanx, this would extend the line another 80 meters, for a total of 1080 meters. This correlates approximately with the c. 900 m frontage of 4000 cavalrymen in Thracian/Macedonian wedges (in which, following a fragment of one of Polybius’ lost tactical writings, each wedge contains 64 men, with a base of 16, and a fi le width of .9 per horseman), although we have no evidence for the specifi c formation used by Antiochus’ cavalry.75 On this hypothesis, the entire Seleucid line facing the legions would have been:

Phalanx and elephants: 550 m Silver Shields and cavalry: 1080 m Galatians: 225 m Total: 1855 m

This would imply that each legion and ala at Magnesia had a front of c. 465 m. Livy reports each legion had a strength of 5400 infantry, with equal numbers in the allied ranks. This implies 1600 hastati per legion and ala. If they maintained a close/open depth of 3/6 ranks, the hastati would physically occupy 360 meters, implying an aver-age gap of c. 10 meters. With a close/open depth of 4/8, the physical front of the hastati would be 270 meters, requiring the gaps cover c. 20 meters apiece. A close/open depth of 5/10 or more would not be possible, given that the gaps would by necessity be larger than the maniple frontages.

ƱƴƤƬƣƮƬпƲƠƨư, ƠҏƲҳƬ ƣҭ ƫƤƲҫ ƲӸư јƲƠƨƯƨƩӸư Ѹ��ƮƳ ƩƠұ ƲԙƬ Ґ�ƠƱ�ƨƱƲԙƬ ƩƠƲф�ƨƬ ї�ƨƱƲӸƬƠƨ ƲƮԃư ƧƦƯрƮƨư. See Xenophon, Hell. 6.4.10 for similar deployment of cavalry in the van of a Greek heavy infantry formation.

74 Bar Kochba, 1979: 8–9, 168 argues staunchly, and in my opinion correctly, that the unlisted strength of the Silver Shields must be 10,000, based on the unit’s listed strength at Raphia, and the fact that a strength of 10,000 helps make Livy’s various contingents add up to his stated total of 60,000 infantry fi ghting for Antiochus III.

75 Aelian, Tactica, 19.5–10. They would have a similar frontage if deployed in the manner described in Polybius 12.18.



Pydna (168 BC): Pydna was by all accounts a confused engagement, as both sides hastily formed battle lines after a brawl over a runaway horse escalated into a set-piece battle, on a broad plain roughly 4 km long.76 Perseus’ heavy infantry consisted of phalangites divided into two divisions of roughly 10,000 each, the leukaspides and chalkaspides (White Shields and Bronze Shields), along with a brigade of 5000 peltasts (Livy’s caetri). The king had in addition an enormous force of c.13,000 light infantry. Many of the details of the battle are swallowed up in an unfortunate lacuna in Livy. Nonetheless, if Perseus managed to eventually deploy roughly 11,000 light infantry (subtracting a modest camp guard), his total battle line would consist of:77

Main phalanx (20,480): 1152 m Peltasts (5000): 281 m Light infantry (11,000): 1237 m Total: 2670 m

The exact number of Greek light infantry fi ghting on the Roman side at Pydna is not stated, but earlier the Romans had been joined by 4000 Attalid infantry, 1500 Achaeans and 100 Apollonians.78 Subtracting 2000 for a camp guard, the remaining Greek infantry would take up c. 400 meters, leaving 2270 meters for the legions and alae, or a frontage of c. 570 meters apiece. This frontage is confi rmed by Livy’s report (perhaps follow-ing the eyewitness account of Scipio Nasica) that Paullus’ I Legio directly engaged the chalkaspides and that II Legio deployed against the leukaspides.79 Each phalanx had a paper-strength of 10,240 men, giving the two opposing legions a frontage of c. 575 m apiece – almost identical to the fi gure adduced above.80

Each legion consisted of 6000 infantry, and this would imply 1800 hastati.81 If a close/open depth of 3/6 was maintained, the hastati themselves would occupy 405 me-ters. To maintain a total front of c. 570, gaps of c. 17 meters would be necessary. If each maniple maintained a close/open depth of 4/8 men, the hastati would occupy 300 meters,

76 For the physical setting of the battle, see Hammond, 1984: 39–40.77 Infantry survivors include 500 Cretans (Livy 44.43.7) and probably the 1000 Thracians associated

with Cotys (who led the retreat, Livy 44.42.2). These perhaps comprised the bulk of the Macedonian camp guard (Perseus also seems to have been surrounded by a large force of cavalry which was not deployed in the battle).

78 Livy 42.55.7–10. This does not count 2000 Attalid troops used to garrison Chalcis.79 Erdkamp, 2006 argues that Plutarch’s account of Pydna derives in part from a Late Annalistic source,

which frequently featured numbered legions. While he is quite correct, this need not negate the veracity of the account. Outside late annalistic sources, numbered legions are attested in a fragment of Cato, see Agnew 1939.

80 Livy implies the strength of the two phalanxes was roughly 21,000 at the start of the war (42.51, subtracting 18,000 enumerated auxiliaries and peltasts from the total infantry strength of 39,000). Perhaps the “paper strength” here was 10,240, or 10 chiliarchies. The suggestion in Haztopoulos, 2001: 75 that each phalanx division had a strength of 12,000, or 24,000 total, is dubiously based on the number of wagons displaying captured shields at Aemilius’ triumph.

81 Livy 44.21.8.


Michael J. Taylor18

requiring large gaps of roughly 27 meters. A close/open depth of 5/10 or greater would not be feasible, given that the gaps would need to be larger than the maniple frontages.

Corinth (146 BC): Mummius fi elded a total of 23,000 Roman and Italian infantry.82 Subtract his picked detachment of 1000 infantry which was designated as a fl anking force, along with a modest camp guard and some Italian soldiers deployed to a forward outpost, and it is a reasonable assumption that his main infantry line consisted of 20,000 troops, with each legion and ala having an average strength of c. 5000.83 The Romans faced a numerically inferior force of 14,000 Achaean infantry. These were presumably drawn up in standard hoplite form, eight deep, producing a line 1575 meters long.84 This would give each legion and ala a front of around 395 meters. If Mummius wished, he could deploy his troops 3/6 deep in close/open order and maintain his maniples seven meters apart. With a close/open depth of 4/8 ranks, gaps of roughly 15 meters would be required to maintain this frontage. A close/open depth of 5/10 or more would not be possible, as this would require the gaps to be larger than the maniples themselves.

Table 2: Induced Frontage of Roman LegionsBattle Induced Legion Gaps Gaps Gaps Front Strength (depth 3/6) (depth 4/8) (depth 5/10)Heraclea c. 320 m 4200 5 m 12 m 15 mCynoscephalae: c. 360 m 4200 9 m 16 m xMagnesia c. 465 m 5400 10 m 20 m xPydna c. 570 m 6000 17 m 27 m xCorinth c. 395 m 5000 7 m 15 m xMean 10 m 18 m 15 m

Conclusion: Minding the Gaps

Constructing the Roman acies with reference to Macedonian battle lines suggests a range of frontages for a mid-Republican legion between 320 and 570 meters, with lar-ger legions having longer frontages. This analysis suggests that the Romans did indeed maintain gaps in their formations during combat (see Table 2 for a summation). The gaps varied substantially based on tactical circumstances, but gaps of c. 10–20 meters

82 Presumably the allied wings were somewhat stronger than the legions, say 5200 apiece in the legions and 6200 for the alae.

83 These were joined by some Cretan archers who were most likely interspersed through the ranks, and some Attalid light troops, who were stationed in a forward outpost that was subsequently overrun by the Achaeans.

84 Battle of Corinth: Pausanias 7.15.7–16.3 While Plutarch reports that Philopoemen had equipped the Achaeans to fi ght as a Macedonian-style phalanx, which might imply a depth of 16, Pausanias (8.50.1) suggests that the Achaeans in the 200s in fact retooled from fi ghting as thureophoroi light infantry into relatively standard Greek hoplites, fi ghting with Argive shields, and presumably in an 8 man hoplite formation. See Anderson, 1967.



may have been relatively standard. It is notable that this evidence does not suggest that the gaps were usually equal to the width of an entire maniple, but rather were generally 25–75 % the width of a maniple front.

The accordion nature of the Roman legion was perhaps one of its major tactical strengths. A commander and his subordinates could easily expand or shrink his front based on the nature of the terrain, the character of his troops, or the strength and disposi-tion of the enemy. For example, the legion spearheading Flamininus’ drive through the Aous pass would need to contract or expand from 200 to 400 meters, as the restricted terrain narrowed or widened.85 Acilius Glabrio, assaulting the gate at Thermophylae, likewise arranged his legions in a narrow front to fi t the topography: ad naturam et an-gustias loci.86 Empty space between the maniples provided much of the tactical fl exibility enjoyed by the legion, as frontages could easily be expanded or compacted simply by altering the size of the gaps, without compressing or dispersing the soldiers within the maniples themselves. These fl exible frontages allowed invading Romans to fi x large numbers of enemy troops with elongated fronts, negating any numerical advantages possessed by opposing forces, so that at Pydna 6000 men in a legion could match over 10,000 drawn up in a Macedonian phalanx.

Gaps would provide suffi cient space for light forces to be expeditiously received through the hastati, and facilitate exchange and relief between the lines of the tres acies. Infi ltration by enemy soldiers would be discouraged by the fact that the gap could be completely covered by missile crossfi re from the Romans stationed on the fl ank of the surrounding maniples. The stationing of the principes immediately behind allowed for immediate reinforcement in the event that the hastati buckled at these weak points.87

It is unlikely that these gaps were completely “empty” during combat. The gaps would also be ideal for the employment of auxiliary light troops such as archers and slingers, as when Sallust reports that Caecilius Metellus “dispersed slingers and archers in between the maniples” inter manipulos funditores et sagittarios dispertit.88 While velites in theory withdrew to the rear, a number of ambitious young men may have lingered in the gaps for the opportunity to score an extra kill. The gaps thus helped integrate light troops into the matrix of heavy infantry. When the Roman army deployed elephants, as it did at Cynoscephalae and Pydna, these were likely initially stationed in the gaps, while Scipio famously used his gaps to channel Hannibal’s elephants at Zama.89 Finally,

85 Hammond, 1966: 50. With a 4200 strong legion and a depth of 8, this would involve gaps transition-ing between 0–20 meters.

86 Livy, 36.18.2.87 Adcock, 1940: 9–10; Sabin, et al., 2007: 429. Polybius 15.13.3 suggests that the principes at Zama

were stationed quite close behind the hastati, in contrast to Hannibal, who had over a stadion (180 meters) between his fi rst and last battle lines (15.11.2).

88 Sallust, Jugurthine War, 49.6. This is also the last textual notice of maniples serving a tactical role in combat. Cf. Herodian 4.15.1, for a similar use of inter-unit gaps in AD 217.

89 Polybius 15.9.7.


Michael J. Taylor20

if any enemy ventured into this lethal funnel, Roman soldiers on either side of the three surrounding maniples might peel off to engage them.

In addition to providing fl exibility to the commander, gaps in the maniples con-tributed to the maintenance of the basic tactical integrity of the entire legion. Gaps prevented bewildered soldiers, whose training and experience might vary substantially, from becoming intermingled with other units, and allowed haphazardly maneuvering maniples to avoid entanglement. Indeed, Rome’s greatest disasters occurred when the gaps were narrowed or eliminated, most notably at Cannae.90 Without the presence of moderate gaps, the Roman legion risked becoming a chaotic and unfocused mass.

The relatively shallow line of legionary infantry, punctuated by gaps, was not without its weaknesses. In particular, it was highly vulnerable to shock charges, evidenced by the retreat of legionary elements before Philip V’s right wing at Cynoscephalae, Antiochus III’s cataphracts at Magnesia and Perseus’ dazzling phalanx at Pydna. In each instance, however, the legions were able to reorganize and counterattack. It is possible that the inter-manipular gaps helped prevent the outbreak of mass panics or mob retreats, by insulating adjacent units from the communal psychological stresses generated within a hard-pressed maniple.91 Ultimately, the fl exible frontage and tactical modularity inher-ent in the manipular legion must remain a signifi cant factor in explaining the relative success of the mid-Republican army on the battlefi eld.

References

Agnew, Malcolm. “A Numbered Legion in a Fragment of the Elder Cato.” American Journal of Philology, 60, 1939, 214–219.

Adcock, Frank. The Roman Art of War under the Republic. Cambridge: Harvard University Press, 1940.Anderson, John K. “Philopoemen’s Reform of the Achaean Army.” Classical Philology, 62, 1967, 104–106.–. “Shields of Eight Palms’ Width.” California Studies in Classical Antiquity, 9, 1976, 349–363.Bahmanyar, Mir. Vanquished: Crushing Defeats from Ancient Rome to the 21st Century. Oxford: Osprey,

2009.Bar Kochba, Bezalel. The Seleucid Army: Organization and Tactics in the Great Campaigns. Cambridge:

Cambridge University Press, 1979. Barnes, Christopher L.H. “Livy 33.8.13 and 35.35.18 Revisited.” Classical Journal, 100, 2005, 363. Bishop, Michael C. and Jon Coulston. Roman Military Equipment: From the Punic Wars to the Fall of

Rome, 2nd Edition. Oxford: Oxbow Books, 2006. Buckland, Paul. “A First Century Shield from Doncaster, Yorkshire.” Britannia, 9, 1978, 247–269.Camp, John M. “A Sculpted Trophy from the Athenian Agora: Preliminary Report.” The Agora Excavati-

on, Reports, 2010. Available online at http://www.agathe.gr/id/agora/report/sculpted%20trophy%202010. Accessed May 21st, 2013.

90 QQ

91 A variation on the point famously made by Du Picq, 1921: 54, which noted that the second and third ranks of a Roman triplex acies were insulated from the terror of the fi ghting taking place in the front ranks.



Canadu, Jose. “Republican Rome and Political Struggles.” In Marasco, Gabriel (ed.) Political Autobio-graphies and Memoirs in Antiquity. Leiden: Brill, 2011.

Coarelli, Filippo. La Colonna di Marco Aurelio. Rome: Colomo, 2008.Connolly, Peter. Greece and Rome at War, 2nd Edition. London: Greenhill Books, 1998. Dekoulakou-Sideris, Ifi genia. “A Metrological Relief from Salamis.” American Journal of Archaeology,

94, 1990, 445–451.Delbrück, Hans. “Die römische Manipulartaktik.” Historische Zeitschrift, 51.2, 1883, 239–264.–. History of the Art of War Within the Framework of Political History (Trans. Walter Renfroe). Westport:

Greenwood Press, 1975.Dobson, Michael. The Army of the Roman Republic: The 2nd Century BC, Polybius and the Camps at

Numantia. Oxford: Oxbow Books, 2008. Du Picq, Charles A. Battle Studies: Ancient and Modern Battle. (Trans. John Greeley and Robert Cotton)

New York: Macmillan, 1921. Eckstein, Arthur. Moral Vision in the Histories of Polybius. Berkeley/Los Angeles: University of Cali-

fornia Press, 1995. Erdkamp, Paul. “Late-Annalistic Battle Scenes in Livy (Book 21–44).” Mnemosyne, 4. S. 59, 2006,

525–563. Hammond, Nicholas G.L. “The Opening Campaigns and the Battle of Aoi Stena in the Second Macedo-

nian War.” Journal of Roman Studies, 56, 1966, 39–54.–. “The Battle of Pydna.” Journal of Hellenic Studies, 104, 1984, 31–47.–. “The Campaign and Battle of Cynoscephalae in 197 BC.” Journal of Hellenic Studies, 108, 1988, 60–82. – and Frank W. Walbank. A History of Macedonia, Vol. III. Oxford: Oxford University Press, 1988.–. “A Macedonian Shield and Macedonian Measures.” Annual of the British School at Athens. 91, 1996,

365–367. Hanson, Victor Davis. The Western Way of War: Infantry Battle in Classical Greece. Berkeley/Los An-

geles: University of California Press, 1989.Harl, Kenneth. “Legion over Phalanx: The Battle of Magnesia, 190 BC.” In Howe, Timothy and Reames,

Jeanne (eds). Macedonian Legacies: Studies in Ancient Macedonian History and Culture in Honor of Eugene N. Borza. Claremont: Regina Books, 2008.

Hatzopoulos, Miltiades. L’Organisation de l’armée macedonienne Antigonides: Problemes anciennes et documents nouveaux. Athens: Fondation nationale de la recherche scientifi que, 2001.

Hoyos, Dexter. “The Age of Overseas Expansion (264–146).” In Paul Erdkamp (ed.) A Companion to the Roman Army. Malden/Oxford: Wiley-Blackwell, 2007.

Judson, Harry P. Caesar’s Army: A Study of the Military Art of the Romans in the Last Days of the Re-public. Boston: Ginn and Company, 1888.

Keppie, Lawrence. The Making of the Roman Army: From Republic to Empire. Norman: University of Oklahoma Press, 1998.

Kimmig, Walter. “Ein Keltenschild aus Ägypten.” Germania, 24, 1940, 106–111.Kromayer, Johannes. “Wahre und falsche Sachkritik.” Historische Zeitschrift, 95.1, 1905, 1–28. –. Antike Schlachtfelder, Band. 2 (Die hellenistisch-römische Periode: von Kynoskephalae bis Pharsalos).

Berlin: Weidmannsche Buchhandlung, 1907. Lazenby, John F. Hannibal’s War: A Military History of the Second Punic War. Warminster: Aris &

Phillips Ltd., 1978. Lendon, Jon E. Soldiers and Ghosts: A History of Battle in Classical Antiquity. New Haven: Yale, 2005. Markle, Minor M. “The Macedonian Sarissa, Spear and Related Armor.” American Journal of Archaeo-

logy, 81, 1977, 323–339. –. “A Shield Monument from Veria and the Chronology of Macedonian Shield Types.” Hesperia, 68,

1999, 219–254.Morillo, Stephen and Michael Pavkovic. What is Military History? Cambridge: Polity Press, 2006.


Michael J. Taylor22

Paret, Peter. “The New Military History.” Parameters, Vol. 21, Autumn 1991, 10–17. Phang, Sara Elise. Roman Military Service: Ideologies of Discipline in the late Republic and Early Em-

pire. Cambridge: Cambridge University Press, 2008. Potter, David. “Caesar and the Helvetians.” In Fagan, Garrett and Trundle, Matthew (eds.) New Perspec-

tives in Ancient Warfare, Leiden: Brill, 2010. Pritchett, Kendrick. Ancient Greek Military Practices (The Greek State at War, Part I). Berkeley/Los

Angeles: University of California Press, 1971. –. The Greek State at War, Part IV, Berkeley/Los Angeles: University of California Press, 1985.Quesada-Sanz, Fernando. “Gladius Hispaniensis: an archaeological view from Iberia.” Journal of Roman

Military Equipment Studies, 8, 1997, 251–270. –. “Not so different: individual fi ghting techniques and battle tactics of Roman and Iberian armies within

the framework of warfare in the Hellenistic Age.” Pallas, Vol. 70, 2006, pp. 245–253. Rawson, Elizabeth. “The Literary Sources from the Pre-Marian Army.” Papers of the British School in

Rome, Vol. 39, 1971, 13–31.Sabin, Philip. “The Face of Roman Battle.” Journal of Roman Studies, 90, 2000, 1–17. –, et al. The Cambridge History of Greek and Roman Warfare, Vol. 1. Cambridge: Cambridge University

Press, 2007.Sage, Michael M. The Roman Republican Army: A Sourcebook. New York/Abingdon: Routledge, 2008. Schneider, Rudolf. Legion und Phalanx: Taktische Untersuchungen. Berlin: Weidmannsche Buchhand-

lung, 1893.Sekunda, Nicolas. The Roman Republican Army. Oxford: Osprey, 1996.–. Hellenistic Infantry Reform in the 160’s BC. Gdaĸsk: Foundation for the Development of Gdaĸsk

University, 2006. –. “The Macedonian Army.” In Roisman, Joseph and Worthington, Ian (eds.) A Companion to Ancient

Macedonia. Malden/Oxford: Wiley-Blackwell, 2011. Scullard, Howard H. Scipio Africanus in the Second Punic War. Cambridge: Cambridge University Press,

1930.Settis, Salvatore, et al. La Colonna Traiana. Turin: Giulio Einaudi, 1988.Snodgrass, Anthony. Arms and Armor of the Greeks. Ithaca: Cornell University Press, 1967. Soltau, Wilhelm. “Die Manipulartaktik.” Hermes, 20, 1885, 262–267. Taylor, Michael J. “Fear the Phalanx.” MHQ, The Quarterly Journal of Military History. Winter, 2011,

10–15. Treloar, Alan. “The Roman Shield: Polybius VI.23.2.” The Classical Review, n.s. 21, 1971, 3–5. Walbank, Frank W. A Historical Commentary on Polybius. Vol. 1–3. Oxford, 1957–1967. Wheeler, Everett L. “The Legion as Phalanx.” Chiron, 9, 1979, 303–318.–. “Firepower: Missile Weapons and the ‘Face of Battle.’” Electrum, Vol. 5 (Roman Military Studies),

2001, 169–184. –. “The Legion as Phalanx in the Late Empire, Part II.” Revue des études militaires anciennes. 1, 2004,

147–175. –. “Greece: Mad Hatters and March Hares.” In Brice, Lee and Roberts, Jennifer (eds.) Recent Directions

in the Military History of the Ancient World. Claremont: Regina Books, 2011. Zhmodikov, Alexander. “Roman Republican Heavy Infantryman in Battle (IV–II Centuries BC).” His-

toria 49, 2000, 67–78.

Department of History Michael J. TaylorUniversity of California, Berkeley3229 Dwinelle HallBerkeley, CA [email protected]


Documents

Historia - RomanArmyTalk · mechanism?2 A still more fundamental question has never been answered ... Roman Infantry Tactics in the Mid ... economic and technological symmetry,