Roman tradition held that they threw out their Etruscan royal rulers in 510-9 bce, though evidence suggests that the Etruscans retained influence in Rome into the 480s. The rest of the fifth century bce saw the city-state, located on a group of hills on the Tiber River in the north end of the plain of Latium, engaged in constant but small-scale warfare against its neighbors for control of agricultural land. The growing population of central Italy and the aggressive role of peoples from the hills around the plain stimulated this warfare, but, for nearly a century, Rome gained no real advantage from it. Indeed, in 390, Gauls from the Po valley sacked Rome itself.
The sack seems to have prompted a reorganization of Rome’s army, for shortly thereafter, Rome began winning its wars regularly and expanding its sphere of influence in central Italy. After the defeat of the Latin League, a coalition of allies who rebelled against Rome’s increasing dominance in 338, the process of expansion accelerated, and by 280, almost all of Italy south of the Po was ruled by Rome (Figure 4.1). This led to conflict with non-Italian powers, first with Pyrrhus, king of Epirus, in south Italy, and then in Sicily with Carthage. The first two Punic Wars, extending from 264 to 202, effectively brought this first phase of Roman history to an end.
During this period of almost yearly campaigning and constant expansion, there was a very tight relationship between Roman social, political, and military organization and activity: Citizenship meant service in the army, and expansion was both the focus of politics and the lubricant smoothing out Roman social conflict.
Figure 4.1 Early Roman Expansion
State and Society
Though lacking kings and the sort of elites found in large, rich states, there was still a large gap separating the rich landowners who dominated Roman social and political life in the early Republic and the small farmers, the poorest of whom were often at the edge of debt bondage, who formed the bulk of the population. The state was run by the Senate, a body drawn from the rich who had served as magistrates—the primarily military leaders elected annually at a gathering of all Roman citizens at the campus Martius, or Field of Mars, the god of war, outside the city. Military leadership and personal glory therefore drove Roman elite politics. Recognition of the vital role of the plebs, or common people, in the manpower of the legions into which Roman forces were organized led to the creation of the office of tribune to represent their interests in the state.
The Roman state around 400 BCE faced two major challenges: increasingly aggressive neighbors, especially the city of Veii, which challenged Rome for dominance in the Tiber valley; and increasing social tension between rich and poor, landowners and debtors. Central to this tension was access to the ager publicus, the public land controlled by the state. For poor farmers, use of a piece of the ager publicus could be the difference between prosperity and debt; for the rich, public land promised even larger, more efficient, and more profitable farms.
Manpower
Warfare was the central activity of both state and society: Every Roman citizen was liable for military service, though the landless or indebted were prohibited from serving in the legions, the heavy infantry core of the army. Citizens with land were divided into six classes by wealth that determined what sort of equipment they owed; the richest served as cavalry, and most of the rest as heavy infantry of one sort or another (see below). Perhaps into the fourth century bce, service was unpaid and voluntary; but, no later than the defeat of the Latin League in 338, and perhaps earlier, the state began to pay regular wages to the army, funded by a special tax instituted for this purpose. Over the course of the period from 400 to 202, probably between 10 and 15 percent of the adult male population served each year in the legions, usually for a term of several years. In times of crisis, such as at the climax of the Samnite Wars or during Hannibal’s invasion of Italy, upward of 25 percent of the adult male population was under arms. The casualties from military service must at times have constituted a stunning proportion of the population as a whole.
Even at these levels of commitment, Roman manpower was inadequate to meet all its military needs. Two mechanisms increased the base of manpower Rome could draw on. First, from early in its expansion, Rome planted colonies of its citizens at strategic locations throughout central (and later all of) Italy. The number of Roman citizens could therefore continue to increase, despite war losses. Second, Rome fought in alliance with other cities from its earliest wars. Although initially voluntary on both sides, Rome came to dominate the relationship with its allies in the sixty years after 400. Military service, indeed, was the key and sometimes only obligation allies owed to Rome.
The Structures and Dynamics of Expansion
In the two decades after 400, the various factors outlined above, in the context both of increasingly successful warfare starting with the final defeat of the rival city of Veii in 396 and of the threat of disaster represented by the Gallic sack of the city in 390, became more tightly tied together into a set of structures that encouraged continual expansion of the Roman state within Italy.
From this point, when Rome won a war, it took land, slaves, and booty from the peoples it defeated.
Each element proved important. The land went into the ager publicus, allowing both the poor and the rich increased access to public land. Of course, more farmland enabled further population growth, maintaining the pressure to acquire still more land, but levels of indebtedness among the Roman poor do seem to have dropped steadily through the fourth century. Some of the land provided the basis for the planting of new colonies, as noted above. Strategic considerations governed the siting of colonies, but the colonies also provided a further outlet for excess population and a source of land for the poor.
Increased access to public land for the rich, however, simply increased their need for labor, a need that could now be met less readily from among the Roman poor themselves, as debt bondage for citizens first declined and then was eliminated by law. The slaves captured in successful wars came increasingly to fill this need. Land hunger and slave hunger thus worked together to unite both rich and poor in support of expansion.
Conquests also added to the circle of Roman allied cities, both through voluntary alliances and among cities that became allies after being initially defeated. Roman statesmanship proved vital in this process. Unlike Greek city-states, which maintained a highly exclusive notion of citizenship even when, like Athens, they built an empire of conquest, Rome was willing to extend citizenship (though, in the case of allies, citizenship without voting rights in Rome) beyond natives of the city itself. The identity of interest this mechanism created between Rome and many of its former enemies was not perfect—some revolted individually, and the Latin War of 340-338 faced Rome with a major coordinated rebellion of allies and colonists. But lenient treatment of the rebels after their defeat seemed to cement their loyalty thereafter, which proved crucial in the Second Punic War. Still, the need to call on allied manpower simply to enforce the terms of alliance, as well as to keep that manpower occupied so it could not be turned against Rome, constituted a further structural incentive to constant expansion.
The politics of glory among the Roman elite contributed a crucial cultural framework for these material causes. Competition for offices and personal glory was the coin of political influence, expressed above all in the institution of the triumph, the public celebration of a general’s military success. Monuments to Roman victories also rose throughout the city, funded by the plunder gained in successful wars. Thus, the dynamics of land and slave hunger, alliance management, and cultural politics all contributed to the pattern of annual campaigning and continual expansion that carried Rome to domination of all of Italy south of the Po by the 270s, and thence to the conflicts with Carthage that would carry expansion beyond the Italian mainland.
We have little direct evidence for the organization and tactics of the early Roman army. Before the Gallic sack of Rome in 390 bce, the Romans seem to have fought in the Greek way, as a spear-bearing phalanx. It was probably clashes with the loose-ordered, sword-wielding Gauls (or perhaps the Samnites) that prompted a reorganization and continuing evolution that resulted, at some point in the fourth or early third century, in the manipular legion, or legion built around the unit of the maniple. This style of legion remained the basic tactical unit of the Roman army into the early first century bce.
Troop Types and Formations
The legion formally comprised four types of troops. The youngest and least experienced served as velites, light-armed skirmishers. Next in age and experience were the hastati, the front line of heavy infantry organized in ten maniples of two centuries each; each century contained 60-80 men. The best veterans formed the principes, the second line of heavy infantry, also in ten maniples of two centuries each. The oldest, most experienced, troops were the triarii, the third line of heavy infantry, whose ten maniples contained only one century each. Thus, a full legion consisted of 3000-4000 heavy infantry, another 600 or so light infantry, and 300 cavalry. Each Roman legion was accompanied by an allied legion, identically organized except for having 300 more cavalry. Two Roman and two allied legions made up a full consular army, capable of fully independent field operations.
The key to the tactical flexibility of the manipular legion was the arrangement and relationship of the three lines of heavy infantry. Each maniple deployed in a block about twenty men across and six ranks deep, with somewhat more space between each rank and file than in a Greek or Macedonian phalanx. The space between maniples equaled the frontage of a maniple, and the second and third lines deployed behind the gaps in the line in front of them, creating a checkerboard pattern. The lines could thus advance or retreat into each other, reinforcing or relieving their tired comrades as needed. The legion’s more open order compared to a phalanx made it easier to maneuver and keep order over rough terrain and more capable of meeting threats to its flanks and rear.
Weapons and Tactics
Changes in weapons accompanied changes in formation. The hastati and principes carried a pilum, a javelin rather than a thrusting spear. It is unclear, however, when the pilum assumed its classic form, with the iron head attached to the wooden shaft by a soft iron sheath or a breakable pin, so that it would bend or crack when it stuck in an enemy shield, simultaneously rendering the shield unwieldy and the pilum useless for throwing back at the Roman line. They also carried a short stabbing sword whose classic form, the gladius, may be of Iberian design, entering Roman use during the Punic Wars. The triarii, the last line of reserve and defense, continued for a time to carry a spear as their main weapon, as well as the gladius. The skirmishers carried javelins, and allied or mercenary missile troops, including slingers and archers, sometimes added to the skirmishing firepower of the legion. The cavalry carried a short spear and a sword, while the heavy infantry wore helmets and body armor. Roman tactics were geared to the attack. Even when receiving an attack, the front lines of a legion would tend to charge as the enemy approached, hurling their javelins from 30 to 50 meters away, then drawing swords for a final rush to hand-to-hand combat.
The legions of the expansionist Republic, though still technically a militia-style force, developed high levels of skill through training (which became increasingly necessary as the Republic grew and men from all over Italy found themselves fighting side by side), extensive experience, and firm discipline, in effect selfimposed as the consuls who led Roman armies were elected. They proved consistently successful against both the looser-ordered, less disciplined forces of Gauls and Italian hill tribes and the denser but less flexible phalanxes of Pyrrhus and later the Macedonians, and were perfectly suited to the varied and often hilly terrain of Italy and the western Mediterranean world. They were the tool first of the Roman conquest of Italy, then of the conquest of Rome’s first imperial provinces.
Consular armies were, it should be noted, far from perfect military machines tactically. Consular leadership, ever-changing and sometimes divided, was usually but not always competent and tended to be unimaginative—apart from exceptional individuals such as Scipio Africanus, victor over Hannibal at Zama (see the Highlights box “Cannae and Zama”). (Of course, on the whole, this makes the record of Roman generalship no worse than any other institutionalized military’s leadership, and the Romans always seemed to find the general they needed in a crisis.) Roman siege craft in this era was deficient compared to that of the Macedonians and Persians. Above all, Roman cavalry was barely adequate—Hannibal’s cavalry exposed it a number of times, crucially at Cannae (see the Highlights box)—and Republican Rome never had to fight on the terrain of or against forces built around truly effective heavy cavalry: Even the cavalry of the Macedonian and Seleucid armies they defeated had declined since Alexander’s day. Still, they eventually triumphed against every challenge they faced.
The strengths and weaknesses of the manipular legionary armies are highlighted by the two most famous battles of the Second Punic War—Cannae and Zama (Figure 4.2).
At Cannae in August 216 bce, a large (over 60,000) but relatively inexperienced army under the alternating command of the consuls Lucius Aemilius Paullus and Gaius Terentius Varro camped in the vicinity of the camp of Hannibal’s army of perhaps 35,000. On August 2, when Hannibal knew Varro would be in command, he moved out to offer battle. With his flanks secured by terrain, he advanced the center of his thin line of Iberian swordsmen toward the Romans. Varro massed his men in a deep, dense block, compensating for their inexperience and hoping to crush Hannibal’s center by force of numbers. By design, Hannibal’s center gradually gave ground, drawing the Romans on.
Meanwhile, his heavy Spanish and Gallic cavalry on his left crushed the Roman cavalry opposite them and rode around the Roman rear to drive away the allied cavalry engaged with the Numidian cavalry on his right. As they did, the heavy phalanxes of African infantry that anchored each end of Hannibal’s line of swordsmen turned inward against the flanks of the Roman column, while the cavalry closed the ring from the rear. What had been a triumphant advance turned to panic, and over 50,000 men squeezed together too tightly to wield their weapons effectively were systematically slaughtered, though 10,000 fought free. Hannibal lost around 6000 men. His double envelopment of the Roman army, the high point of his military career, has remained a classic in studies of the “art of war” ever since.
The tables were turned in March 202, however. This time, Hannibal had the larger (48,000 man) but more inexperienced army, facing Scipio Africanus’s 34,000 seasoned veterans and 9000 allied and Numidian cavalry. Hannibal counted on a number of war elephants to create an advantage for him, but Scipio made use of the flexibility of the manipular formation to line his maniples up with the gaps aligned, creating lanes through which the elephants were driven with minimal disruption of the Roman infantry. The Roman cavalry forces then drove off the Carthaginian horse while Scipio’s hastati and principes cut down Hannibal’s first two lines of inexperienced infantry. Hannibal’s veteran third line (the three-line formation reflecting Roman influence on Hannibal’s tactics) resisted the Romans, now joined by the triarii, until the Roman cavalry returned from the pursuit and charged the rear of their formation. Hannibal escaped, but 20,000 of his troops died and another 15,000 were captured, compared to losses of 1500 Roman dead and several thousand wounded.
Both battles illustrate some common features of ancient (and most premodern) battles. For one thing, the surest way to defeat foes was to panic them. Aside from killing or driving off their leader (as Alexander had done at Gaugamela), this was most easily accomplished by getting to the flanks and rear of their formation. This gave cavalry an important role even in infantry-dominated battles. And most casualties happened in the pursuit (or, as at Cannae, slaughter) phase of the battle, as it was much easier to kill a man who was no longer actively resisting. Finally, although numbers often mattered, experience could count even more: A steady, veteran formation could maintain its cohesion under pressure much more readily than even well-trained new recruits, and so could carry the day in the face of superior numbers.
Figure 4.2 The Battle of Cannae
Strategy and Grand Strategy
That Roman wars almost always ended in victory was only partly due to the adaptability and tactical efficiency of the legions, however. Their most remarkable triumphs came as much despite massive tactical defeats (especially against Hannibal) as because of battlefield victories. To explain this, we need to examine Roman strategy and grand strategy under the expansionist Republic.
Roman strategy is probably best characterized as the direct approach. Roman leaders at war tended to lead their armies straight at the crucial positions, whether cities or armies, of the enemy, aiming to defeat their main force directly. Such an approach could lead to disaster—Hannibal exploited the tendency in destroying three Roman armies in a row in the first two years of his invasion of Italy, turning Roman aggression against itself. But it just as often served to draw Rome’s enemies into a direct and sometimes attritional struggle in which Rome’s usually superior manpower and grand strategic will could carry the day. Therefore, the direct approach was probably one benefit of the rotating consular system of generalship, as each consul, elected only for a limited term, wished to earn glory (and a triumph) as quickly as possible. It took a dictator (a temporarily appointed emergency military commander), Quintus Fabius Maximus, appointed in the aftermath of defeats at Hannibal’s hands at Trebbia and Lake Trasimene, to follow a more cautious strategy. In the process, he earned the nickname Cunctator, or “The Delayer,” reflecting the ambivalence with which even a successful indirect approach was met in Republican Roman military culture.
The direct approach in strategy was matched by a grand strategic approach that is best characterized as relentless. Expansionism, as we have seen, was built into the social and political structures of the early Republic, which is why we are calling it the expansionist Republic here, and thus constitutes an implicit grand strategy. But it was in the face of real threats to Roman survival that the true character of Roman grand strategy emerged: They refused to consider surrender and inevitably simply outlasted the political and military will of their opponents. The fanatical determination of the Roman Senate casts the halfheartedness and in-fighting of the Carthaginian Senate in a particularly harsh light. Relentless, ferocious aggression thus lay at the heart of Roman military practices from the grand strategic to the tactical and individual levels. They were true heirs of the Assyrians, and comparable to their contemporaries the Qin, in this regard.