The Sword of Rome

by Jeremiah McCall

  Any account of the Roman army in the middle Republic must begin with Polybius, who took time in his history to describe the soldiers, their equipment, and organization.27 The largest unit in the Roman army of the middle Republic was a legion. Though the actual strength could vary with the recruits available and the conditions in the field, on paper each legion consisted of approximately 4,200 soldiers, 5,000 during emergencies. Each legion had four categories of infantry. These categories were determined by the age of citizens, their wealth, and – because citizens provided their own weapons and equipment at this stage in the Republic – their panoply. The youngest soldiers, those closest to the minimum recruit age of seventeen, were the velites. As the light infantry of the legion, they were also the lightest equipped, armed with javelins and a sword, and protected by a round shield, but little or no body armour. In the framework of ancient warfare, light infantry tended to serve as missile troops. They harassed enemy armies within reach of a javelin and screened the movements and deployment of their own comrades in the heavy infantry. The velites also were commonly used in combination with cavalry as skirmishers and more mobile squads employed to occupy advantageous or critical positions quickly.

  Diagram 1: Standard components of a Roman legion.

  Diagram 2: Typical Roman army with Roman and allied forces.

  The main infantry line was manned by the hastati, principes, and triarii. All were heavy infantry soldiers, armed and equipped to fight in close quarters against enemy combatants. The hastati were younger than the principes, the men in their prime, while the triarii consisted of older soldiers closer to the maximum service age of forty-five. The core of these soldiers’ panoply was the scutum, an oblong or rectangular shield some 4 feet high and 2.5 feet wide. According to Polybius, who certainly was in a position to know, the shield consisted of a convex core of wood covered with canvas and hide, perhaps ¾ of an inch thick overall, with a central iron boss and grip. Since the average Roman male was well under 6 feet tall, the shield effectively covered the entire body of the soldier and could also assist in driving back an enemy. For body armour the heavy infantry wore a square bronze plate perhaps 9 inches to a side that protected the centre of the chest. Wealthier soldiers supplied their own mail coats. Finally, all these soldiers wore a helmet with a crest. For weapons, all three classes of soldier had a gladius, the short, sharp Roman sword useful both for stabbing and slashing, and the hastati and principes also had pila, heavy javelins. The triarii, by contrast, bore long, sturdy thrusting spears rather than pila. This fit with their primary role as a reserve line used to provide a defensive spear wall should the hastati and principes be driven back in battle. In a given legion of 4,200 there were, on paper at least, some 1,200 velites, 1,200 hastati, 1,200 principes, and 600 triarii. These troops were subdivided into maniples, smaller tactical units that could maneuver and deploy far more flexibly than the larger legion of which they were a part. Each maniple consisted of perhaps 120 soldiers plus velites, who were divided among the maniples.

  In addition, each Roman army was, so far as we know, accompanied by an allied contingent of soldiers. The allied infantry were armed and equipped like their Roman counterparts and in Marcellus’ day at least equaled the number of citizen infantry in any standard army. With the exception of the extraordinarii, the hand-picked elite infantry from the allies, the bulk were divided into two forces labeled the left and right wing.28

  The cavalry forces of a Roman army consisted of citizen and allied cavalry. On paper, each legion had a citizen contingent of 300 cavalry and an allied contingent of somewhere between 600 and 900. The cavalry were subdivided into turma of thirty riders to allow for tactical flexibility. Throughout the Republic they were armed with spears and swords and protected by shields. At some point, perhaps early in the Second Punic War, they abandoned their light shields and adopted the heavier protection of Greek-style shields and mail cuirasses.29

  So much for the basics of equipment and organization. A critical question remains: what was a Roman battle actually like for the combatants? Warfare for the Romans, and indeed most Mediterranean and European peoples of the period, was fundamentally similar in that clashes between large formations of heavy infantry were the basis of most battles. Soldiers arranged in more-or-less close order – roughly shoulder-to-shoulder or up to several feet apart – stood close enough to their enemies to fight with melee weapons. Combat in these circumstances was intensely physical, personal, and brutal. One had to stand close enough to one’s enemy to strike with spear and sword. In practice, this meant a distance of several feet – a grim prospect indeed, and strikingly different from contemporary war, where it is possible for combatants to be separated by thousands of miles.

  For the Greek world from the seventh to the fifth centuries, heavy infantry combat revolved around the phalanx, a solid formation of infantry armed with spear and shield. The phalanx was a tactically inflexible unit compared to other formations. It relied on presenting the enemy a murderous wall of shields and spears to win the day, not complicated deployments and flanking maneuvers. Battles between phalanges tended to be relatively swift and one-sided. The men in the opposing phalanges charged one another, each side seeking to break the morale of the other at the very onset. On many occasions, the charge itself was sufficient to decide the battle. The soldiers on one side proved unwilling to receive the enemy charge and fled at – sometimes even before – the first clash of shields and spears. When the initial charge did not decide the matter, the heavy infantry settled into a match of stabbing and shoving, each side attempting to disrupt the other side’s formations. When one side broke, the battle was over, the defeated fleeing and the victors often pursuing the defeated for a time, engaging in the type of indiscriminate slaughter that served as an object lesson in the ancient world. Phalanx battles were generally characterized by their lack of grand maneuvers and tactical flexibility.

  By the fifth century, however, and in the Hellenistic period where the successors of Alexander the Great plied their martial trade, cavalry, light infantry, and missile troops became more important components of the army. Consequently, the tactical options available to commanders increased. The core of the armies, however, remained the massed-infantry phalanx – though the shield had shrunk considerably and the spear extended from six to eight feet into a pike that could in some circumstances be over twenty feet long.

  The Roman army did use the phalanx at an early stage in its development, but transitioned to the manipular army, which was well-established by the middle Republic. Though the idea of a typical battle is highly misleading, the Roman armies do seem to have had a somewhat standard approach to battle with the manipular army. Certainly, Polybius had a penchant for mentioning in his battle descriptions that the Roman army was deployed in the ‘usual order’. Based on his accounts30 the general order went as follows. The army would deploy with the heavy infantry maniples forming the centre of the Roman battle line, presumably hastati in front, principes next, then triarii. The allied infantry, organized into left and right wings, occupied the appropriate space to the left and right of the citizen infantry. The light-armed velites took position in front of the battle line, and the cavalry, often separated into citizen and allied contingents, occupied the left and right flanks of the battle line. Initially, it was the task of the velites to begin the battle by casting their javelins at the enemy forces, seeking to wound and demoralize them before the main struggle. Once their missiles were exhausted or the closing of the enemy heavy infantry forced them back, the velites retired, presumably through the gaps in the maniples, and the main infantry lines engaged.

  Though the exact operation of the manipular legion in battle is far from clear, the maniples clearly provided a tactical flexibility missing from the phalanx. Typically, the maniples deployed in a quincunx formation. In short, each maniple in the first line was separated from the maniples on either side by a gap slightly more than a maniple’s width. The second line was offset accordingly so tha
t each maniple in it was aligned with the gaps in the first line, and the third line mirrored the first, as in the diagram below.

  Diagram 3: Infantry maniples in a quincunx formation.

  Theoretically, this arrangement allowed the second line maniples to move forward and relieve the first line, which retreated through the gaps. The third line was occupied by the triarii who ordinarily did not enter battle unless things had gone very poorly for the hastati and principes; in this case the triarii formed a defensive spear wall and bought time for the others to rally and reform.

  When the heavy infantry clashed, the most important battle was not on the field but in the mind. Morale, the psychological will to fight, determined success or failure on the battlefield. Modern historians of ancient battle who recognize this reality pay their respects to Colonel Ardant du Picq, a French officer in the latter half of the nineteenth century who wrote a study on the power of morale in ancient combat.31 He asserted that ancient battles were not to be understood as simple brawls where formations disintegrated upon contact with the enemy and combatants became hopelessly intermingled in an archipelago of single combats. Such an understanding violates both the available evidence and the soldierly common sense that du Picq brought to his subject. Rather, only the front ranks of each infantry formation fought in actual hand-to-hand combat. Meanwhile, the rear ranks felt extraordinary amounts of stress as they waited for their turn in battle, watching the struggles just a few yards in front of them, but having no outlet for their stress. It was in the rear, not the front, that ancient armies were most often defeated. If the pressure of watching and waiting became too great, if the fear of death and defeat overwhelmed, the soldiers in the rear ranks would give way first – those in the front simply had no place to go with the ranks behind keeping them in place. Once the soldiers in the rear began to run, the formation lost its cohesion: individuals fled for their own safety, the front lost the moral support of comrades behind it, and the unit collapsed.

  Ironically, though individuals’ overwhelming fears of injury and death caused them to break ranks and seek safety, it was the very breaking of ranks that exposed them to the greatest danger. So long as an infantry formation stayed intact, any individual’s risk of death or wounding was much less. When a formation dissolved and individuals turned in flight, however, they lost the safety of their comrades’ protection and exposed their backs to the enemy and to slaughter. There was a reason why, when a Roman felt the desire to publicly display his scars in order to reaffirm his virtus to the crowd, he made sure to point out that none were on his back. Being wounded in the back only occurred when one had fled the battlefield; fleeing the battlefield meant deserting one’s comrades and leaving them as easier prey for the enemy.

  The key to victory on the battlefield, then, was to ensure that one’s own soldiers could withstand the pressures of battle – the shouts, the scraping and clanging of metal on metal, the grunts and screams of those fighting and dying. When enough soldiers were sufficiently distracted and frightened so that the compulsion to flee overwhelmed any obligations to stay in their positions in the group, the effectiveness of the combat unit was lost. Unless rallied, the individuals in the unit would seek their own safety by retreating or, if sufficiently demoralized, fleeing the battlefield. The victors, meanwhile, had the opportunity to slay as many of their fleeing opponents as possible – here cavalry helped charge down the defeated.

  Applying this understanding of the Roman army to the strategic situation in Etruria in 225, the trapping of the Gallic army between two Roman armies meant that the Gallic force had to split to meet both foes, or fight with its backs vulnerable to one. Either proposition would be demoralizing for the Gauls and encouraging for Romans. Building on this advantage, Atilius opted to add an additional vector of attack; seeing a nearby hill that the Gallic forces would eventually pass, he rode with his cavalry to occupy the hill and threaten the Gallic flank. The Gallic forces eventually arrived and, apparently unaware that Atilius’ cavalry on the hill belonged to a different army than the one they knew was pursuing them, sent mixed forces of cavalry and light infantry to contest the hill with the Romans. Soon learning of their tactical dilemma, however, the Gauls formed two battle lines, one facing forward toward Atilius’ legions, the other rear toward Aemilius.32

  Aemilius, for his part, learned that the Gallic army was penned in, observed the struggle along the hillside flanking the Gauls, and sent his own cavalry forces to aid Atilius. According to Polybius, so many cavalry were engaged that both armies observed the battle on the hill for quite some time. Indeed, if all the citizen and Italian cavalry from both armies were engaged, thousands of horses and riders were swarming about the hill, surely a spectacle. As the struggle to take the hill continued, the infantry forces engaged. According to Polybius, the Insubres and Boii wore only their trousers and light cloaks as protection, in addition to carrying shields, smaller than those of the Romans. The Gaesatae, however, opted to fight naked though still with their shields, trusting that their physical superiority to average Romans, in addition to the bravery of the decision itself, would demoralize their foes.

  Though the tactical situation certainly favoured the Romans, who had the Gauls hemmed in on both sides, the battle was far from a foregone conclusion. The battle began, as was often the case in the Roman world, with the velites casting their javelins into the mass of the Gallic infantry. Wounded by the javelins, the naked Gaeseatae lost their stomach for battle and panicked. They broke and either fled back into the lines of their comrades, causing disruption wherever they went, or flung themselves futilely upon the orderly Roman formations. Despite the chaotic break of the Gaeseatae, the lines of Insubres and Boii stood firm and met the Roman maniples in hand-to-hand combat. Polybius assessed the strengths and weaknesses of both sides:

  [The Gallic infantry] met the enemy and kept up a stubborn hand-to-hand combat. For, though being almost cut to pieces, they held their ground, equal to their foes in courage, and inferior only, as a force and individually, in their arms. The Roman shields, it should be added, were far more serviceable for defence and their swords for attack, the Gallic sword being only good for a cut and not for a thrust.33

  During the infantry melee the Roman cavalry had finally seized the hilltop, though the consul Atilius died in the engagement. Now ideally positioned to punish the flanks of the Gallic infantry, the Roman cavalry charged down the hill and attacked. It is important to note that when Roman cavalry charged, the goal was not to collide with the enemy. Even if a horse could be impelled to collide with a solid wall of men, such a maneuver would only destroy an extremely valuable warhorse, and incapacitate or kill an elite rider, at the cost of a few inflicted casualties – hardly a reasonable trade off from the Roman perspective. Rather, the goal was either to frighten the enemy to give way or to work into the open spaces between soldiers and disrupt the formations. The flanks of infantry formations were especially vulnerable to such attacks since shields and weapons normally faced forward. In this case, the pressure on three sides by Roman forces, and the disruption caused by the cavalry, in addition to the additional casualties inflicted as a result of the disruption, proved decisive. The infantry formations collapsed, and tens of thousands of were slaughtered by the Romans.34 According to Polybius, most of the Gauls were cut down in the field – 40,000 by his estimate – while another 10,000 were captured. These prisoners became part of the spectacle that was Aemilius’ triumph, a formal procession held in the city to celebrate the crushing victory.35 Their invasion blunted and their military might disintegrated, the Insubres and Boii fell prey to Roman invasions for the next two years. In 224, the consuls subdued the Boii and forced them to surrender.36 In 223, the consuls defeated an Insubrian army in its own territory, a decisive blow that pushed the Insubrians to sue for peace.37

  So, the Insubrians sent emissaries to Rome, and it is at this point that Marcellus appears in the accounts. According to Polybius, the Insubrians were authorized to accept any
conditions the Romans cared to impose in return for peace. The consuls of the year, Marcellus and Gnaeus Cornelius Scipio, however, insisted that the Insubrian emissaries should be dismissed and the war continued.38 Plutarch includes additional details: in his version the senate was generally open to reaching a peace agreement but Marcellus in particular – he does not mention Scipio in this context – tried to move the popular assembly to continue the war.39 Plutarch’s account, however, is confused. He suggests that peace was made despite Marcellus’ efforts and that it was the instigation of the mercenary Gaesatae that continued the war into another year. It makes little sense that the Insubrians would so desperately seek peace, a point on which Polybius and Plutarch agree, and then immediately renew the war after receiving peace – all at the instigation of their hired warriors. So it seems that Polybius’ version, in which both consuls agitated for war, is to be preferred for its lucidity.

  There are two points worth keeping in mind when considering the testimony of Polybius and Plutarch. First, Marcellus and Scipio were neither the first nor the last consuls to push for war when peace was in reach. The consulship was a rare prize in an aristocratic career. Since there were only two consuls elected every year, most Romans who entered the senate would never hold that office. Those who did manage to win the office so coveted among the most powerful and prestigious aristocrats would very likely never be consul again. This meant they had to make the most of their one year in office, and there was no surer path to glory than to prosecute a war successfully. A year of peace generally meant a year of relative insignificance for a consul.40 Not that such years were common; it is a good guess that the Romans only had a handful of years free from war in the Republic.