Two legionaries depicted on a first-century ad relief from the principia or headquarters building in the fortress at Mainz. The man on the right stands in the classic fighting posture of the Roman soldier, crouching to gain as much protection as possible from his scutum, ready to deliver an underarm thrust from his short sword. The men wear a version of the Imperial Gallic helmet, but it is not clear whether any body armour is shown.
Polybius claims that Scipio Africanus told his troops before the battle of Zama that they were fighting not just to defeat Carthage, but for the domination of the world. In Polybius’ own lifetime Rome had become the greatest power in the Mediterranean. A century and a half later, when the great period of expansion ended with the death of Augustus, the Empire’s frontiers lay on the Atlantic coast, the Rhine and Danube in Europe, and the Euphrates in the East. Apart from a few later additions, the basic shape which the Roman Empire was to maintain for over four centuries had already been established. This chapter will tell the story of these vast conquests. It will also describe how the citizen militia of the Republic changed into a professional army of long-service soldiers recruited from the marginal elements of society.
Before considering how the Romans created this vast Empire, it is worth pausing to discuss why they did so. For a long time it was believed that the Romans were not willing imperialists, but had been drawn on to fight war after war to defend themselves and their allies against real or imagined threats. This view was most popular at the beginning of the twentieth century when the great European empires still held sway over most of the globe, and the rule and improving influence of the civilized over the uncivilized was accepted as an inherently good thing. It was attractive when emphasizing the benefits of Roman civilization to view the acquisition of their Empire as accidental, rather than motivated by a blatant desire for power and wealth. In the last few decades, when the memories of empire seem so distant, a generation of scholars for whom imperialism is associated not with progress, but with exploitation and repression of indigenous cultures, have adopted a far more hostile attitude to Roman expansion. They have claimed that Roman society was geared towards annual aggressive warfare, and concentrated in particular on the requirement of the aristocracy for military adventures.
This auxiliary infantryman from another of the Mainz reliefs carries an oval shield and at least two javelins in his left hand, whilst brandishing another in his right. Throughout her history Rome relied heavily on soldiers who were not Roman citizens, who usually made up at least half of any force.
Roman Empire ad 14
The century up to the death of Augustus sate the most rapid and continuous expansion in Rome's history. A series of gifted commanders at the head of the new professional legions carved out fresh provinces in Europe, Africa and the East. During these years Roman soldiers crossed the Rhine and Euphrates, reached the Elbe, explored the deserts south of Egypt, pushed around the shores of the Black Sea, and landed in Britain.
The men who governed Rome’s provinces and commanded her armies were senators following a well-defined career pattern, known as the cursus honorum, which involved a mixture of civilian and military posts. War and politics were inseparably linked at Rome. Politicians did not advocate specific policies or belong to anything resembling modern political parties, but were elected to magistracies largely on their own and their family’s reputation; the system favoured the members of the old aristocratic families who could boast of the great achievements of their ancestors. The numbers in each college of magistrates declined in proportion with its seniority, and only a small minority of the Senate’s 300 members could ever hope to hold one of the two annual consulships. Competition was fierce to gain election, and then even more intense to achieve distinction during a man’s year of office, so that he returned to assume the influential place in the Senate befitting his great reputation. The greatest prestige came from military success, and a magistrate who had held supreme command in a victorious war won the right to celebrate a triumph, riding in a chariot through Rome to the acclamation of the whole city. Even the men who had achieved this honour vied with each other to stage the most spectacular triumph, or to build the greatest monument and stage the most lavish games to commemorate it. Flamininus, Scipio Asiaticus, Manlius Vulso and Aemilius Paullus, all of whom had fought successful wars in the Hellenistic east, were each credited with staging a triumph that was greater than any that had preceded it. Each one had also to stave off political attacks from rivals who did not wish them to receive the honour.
A provincial governor usually had only a single campaigning season in which to fight a successful war before he was replaced by another man equally ambitious for a military adventure. Many arrived in their province impoverished by an expensive election campaign and needing a quick profit. The booty of a victory was considerable, especially in the richer east, and there were always captives to sell into slavery. Returning to Rome, the successful commander displayed his prestige in the size and splendour of his house in Rome and his servile household, and invested in vast rural estates worked by a labour force of slaves. Competition for status among the Roman aristocracy demanded frequent warfare, and it is not surprising that some Roman generals provoked a war for their personal glory. Gnaeus Manlius Vulso arrived to take over the army in Asia after the victory at Magnesia. Having vainly tried to provoke Antiochus to break the peace and restart the war, in 189 вс he launched an unprovoked attack on the Galatians, three Celtic tribes who had settled in Asia Minor a century before. On his return to Italy he was criticized for fighting a war without the approval of the Senate and People of Rome, and only narrowly escaped condemnation after mobilizing all his friends and relatives among the senators. In this view Roman expansion was the result of a never-ending search for fresh peoples to defeat and loot in order to supply the aristocracy’s demand for wealth and glory, and maintain a constant supply of the slaves on which the economy of Italy had become based.
In a triumph the successful commander rode in a four- horse chariot, his face painted red and dressed like the statue of Jupiter Optimus Maximus. To celebrate a triumph was the highest ambition of most senators, adding not only to his own glory, but that of his family. A slave stood behind the general, holding the laurel wreath above his head and whispering reminders that he was a mortal, even though he wore the regalia of a god. Under the Principate only members of the Imperial family were allotved to celebrate a triumph, as in this relief the Emperor Vespasian’s son, Titus, commemorates his capture of Jerusalem in ad 70.
Vast numbers of slaves were taken during Rome’s wars of expansion, the profits from their sale going primarily to the army commanders. During his Gallic campaigns, Caesar sold hundreds of thousands of captives into slavery and was able not only to pay off his enormous debts, but amass a vast fortune. These naked captives, chained together at the neck, are from another of the Mainz Reliefs. They are probably Germans, or perhaps Celts, since their spiky hair may indicate the latter’s practice of washing it in lime.
There were blatant examples of such triumph hunting, but its extent should not be exaggerated. Some provinces offered plenty of opportunities for fighting a campaign which could be presented as being in Rome’s interest. The frequency of small-scale warfare against Spanish, Thracian and Gallic tribes led to a law being passed stipulating that at least 5,000 opponents needed to have been killed in battle for the victorious commander to be eligible for a triumph. However, the culture of the Roman aristocracy did not always lead to constant annual war making, and some consuls seem to have made little effort to secure themselves a military command. Competition among senators sometimes had the effect of curbing expansion. The Roman constitution was based around the principle that no one element in the state, and certainly no single politician, should hold overwhelming power. Magistracies were held for only a year, and there was always at least one colleague of equal rank. While politicians were eager to add to their own reputation, they were even more keen to prevent rivals from gaining too much influence.
There is much truth in this picture of senators as inherently aggressive, but it is far too simplistic as an explanation for Roman imperialism. Rome may have appeared geared to constant annual warfare, but in fact the intensity of Roman war making and expansion varied immensely. There were periods of several decades during the second century вс when very few wars were fought, and then only on a small scale, and much of the great territorial expansion occurred in short, intense bursts. The Romans were not unusual in fighting frequent wars, but the relentless quality of their war making was distinctive. As we have seen in the last chapter, a Roman war could only end when the enemy ceased to be a threat, having either been absorbed as a subordinate ally or destroyed as a political entity. If this outcome was not fully achieved in a single war, then further conflicts were almost inevitable until the Romans had achieved their aim.
The Romans provoked the Third Punic War (149—146 вс) and utterly destroyed Carthage when they felt that she was starting to re-emerge as an independent power, having finally paid off the indemnity of the Second Punic War. A defeated enemy did not necessarily need to be annexed and turned into a province. In fact the Romans were reluctant to establish new provinces and increase the number of overseas garrisons supplied by their citizen army. After the Second Macedonian War, the kingdom’s power was curbed, but it retained its independence. Following the Third War the kingdom was dissolved and replaced by four self-governing regions. It was only when these regional governments had failed to cope with the invasion of the pretender Andriscus and the Fourth War that the Roman province of Macedonia was created. Nor were the Romans always swift to exploit the resources of their provinces, and it was several decades after the creation of their Spanish provinces that they began to derive much benefit from the area’s mineral wealth.
Roman expansion was a complex process which varied in intensity and nature. If one characteristic typifies the Romans (and especially the senators) at this period it was their supreme self-confidence. Roman senators had long come to consider themselves the equal of any foreign king. Their attitude was reflected in the confrontation between the Roman embassy, headed by the ex-consul Gaius Popilius Laenas, and Antiochus IV of Syria in 167 вс. When the Seleucids invaded Egypt, Rome did not send an army to defend her ally, but only a small group of commissioners. When Antiochus politely offered his hand to Popilius, the Roman brusquely thrust a tablet containing the Senate’s ultimatum into it. The king, faced with a demand for his immediate withdrawal from Egypt, said that he would discuss the matter with his advisers before giving a reply. The impatient Popilius used the point of his staff to draw in the dust, enclosing Antiochus in a circle and demanding an answer before he stepped out of it. The astonished king accepted the terms without question. The Roman attitude to foreign powers was often high-handed, frequently reverting to the use or threat of force.
In 225 вс the last great Gallic raid into central Italy was trapped between two consular armies and destroyed. For the next fifty years the Romans assumed the offensive against the Celtic tribes of that area of northern Italy known as Cisalpine Gaul. Hannibal’s arrival encouraged renewed hostility, and one Carthaginian officer, Hamilcar, continued to lead the tribes against Rome for several years after the Second Punic War, until he was killed in battle. The fighting in Cisalpine Gaul, only a few hundred kilometres from Rome, was closely supervised by the Senate, which committed considerable resources of manpower to the subjugation of the area.
Battles fought against the Gallic tribes were in many ways similar to those fought against Carthaginian or Hellenistic opponents. There were the same delays and ritual challenges before a battle, each side reluctant to risk combat until every possible advantage had been gained. Normally the Roman generals outclassed Gallic leaders in this tentative manoeuvring much as Hannibal had outclassed the first Romans sent against him. Tribal armies were clumsy and it was difficult for their leaders to manoeuvre them during a battle. They were composed of two elements: the warrior bands supported by each nobleman and the mass of the ordinary tribesmen. Noblemen displayed their status by the numbers and fame of the warriors who lived at their expense under an obligation to fight for them. These bands were semi-permanent and provided a well- equipped and highly motivated nucleus to any Gallic army. They were far outnumbered by the mass of ordinary warriors composed of all free tribesmen able to equip themselves, and loosely grouped by family and clan relationships. Gallic leaders fought at the head of their followers, inspiring them by their personal prowess. Tactics were simple, and relied on a headlong charge by a screaming mass of warriors. The first charge of a Gallic army was a dreadful thing, but the Romans believed that if they could withstand this onslaught then the Gauls would steadily tire and become vulnerable. Classical literature claims that the barbarians were poorly conditioned and easily tired by strenuous activity and heat. But probably the main reason why the Romans were likely to win a prolonged combat was their triplex acies formation that allowed them to reinforce threatened parts of the line. Individually the Romans were better equipped and armoured than the majority of Celtic warriors, but there is little indication of the great superiority which Caesar’s troops in the first century вс would display against similar Gallic opponents. Gallic armies did successfully ambush Roman columns on the march, for instance destroying most of the army commanded by the praetor Lucius Postumius in 216 вс, but this was only possible when the Gauls had had enough time to muster their whole army along the likely route of the Roman advance. Mustering a Gallic army and then deploying it for battle was a slow procedure, and it is notable that very often tribes were unable to form an army until the Romans had attacked their territory, ravaged their fields and then begun to withdraw.
Caesar’s campaigns in Gaul
Benefiting from a political alliance with Pompey and Crassus, Julius Caesar was able to secure an extraordinary five- (later extended to ten-) year command of the two Gallic provinces and Illyria. Early interventions in Gallia Comata ('hairy Gaul’, the area outside the Roman province) against the migrating Helvetii and the German war leader Ariovistus, led on to further conflicts with more distant tribes, till Caesar’s legions had subdued the whole area. To attract public attention at Rome, Caesar staged two expeditions to the mysterious island of Britain. He was to face two major rebellions, one in the winter of 54-53 вс amongst the Belgic tribes and another a year later uniting much of Gaul under the leadership of Vercingetorix. Caesar left Gaul a rich man, his wealth mostly derived from the hundreds of thousands of captives sold into slavery, at the head of an efficient and fanatically loyal army willing to fight against his political opponents.
Siege of Alesia
In 52 вс Vercingetorix attempted to stance Caesar’s army into submission, refusing to join battle and trying to cut them off from supplies. Caesar pursued the retreating Gallic army, eventually cornering them in the hill town of Alesia. There he fenced the enemy in with twin lines of fortification, repulsing the massive relieving army sent to save the Gallic leader. Eventually, unable to break out, Vercingetorix surrendered, in one version laying bis arms at Caesars feet and then sitting down, mutely waiting to be led away.
Opposite: The Via Appia connecting Rome with Capua and the Campanian plain was built in 312 вс under the orders of the censor, Appius Claudius Caecus. An important aspect of Rome’s absorption of conquered territory was to construct roads linking new colonies to Rome and, increasingly, to each other. Built on a monumental scale, Roman roads combined practical utility with visually impressive statements of power.
Vercingetorix was a chieftain of the Arverni who managed to unite most of the tribes of Gaul and lead them in a massive rebellion against Caesar in 52 вс. Forced to surrender at the siege of Alesia, he was imprisoned and eventually suffered the fate of many enemy leaders, being ritually strangled in Caesar’s Gallic triumph.
One heavy defeat in battle was usually enough to force a Hellenistic monarch to seek terms. Each Gallic tribe was separate and had to be defeated in turn. A victory over a neighbouring tribe might overawe other peoples, but it did not in itself force them to capitulate. When every free male in the tribe was able to fight as a warrior, battle casualties were easier to absorb than among professional armies. Not only that, but the tribes themselves were divided into clans and factions. Most included a number of powerful chieftains or sub-kings, one of whom might be recognized as the monarch of the whole tribe. Each leader headed a faction within the tribe which would grow or decline depending on his achievements, and the numbers of warriors whom he attracted to any expedition varied according to his reputation. A peace negotiated with a tribe did not guarantee the acceptance of all its members. Warfare played a central role in Gallic society. Leaders needed wealth to support their band of followers and the most common way of gaining this was by raiding. Raids and counter-raids figured heavily in the campaigns in Cisalpine Gaul. A favourite target for the Celts were the colonies which the Romans had settled north of the Po, and these were frequently beleaguered and sometimes sacked.
The settlement of large numbers of citizens in colonies in Cisalpine Gaul was an unusual feature of Roman imperialism at this period. Their presence was an added source of friction with the Gauls and Ligurians, as the settlers pressed for more land and divided up confiscated tribal territory into regular squares by the Roman process of centuriation. They emphasized the permanence of Roman occupation, as did the roads that were constructed. Earlier Roman roads had always begun at Rome itself, linking the city directly to a new area of settlement. In 187 вс the Via Aemilia was constructed connecting the two colonies of Arminum and Placentia, the first Roman road designed to be excessively straight. A straight line may be the shortest distance between two points, but it is seldom the easiest route, and a road stretching straight from one horizon to the next was a powerful statement of control over conquered territory. It was also, in that characteristically Roman way of combining the impressive and the practical, a valuable means of strategic movement. The process of consolidating and organizing the province continued throughout the century, converting individual settlements linked to Rome into a coherent unit. At the same time, the Romans’ attitude towards their Empire as a whole began to change, and it gradually began to assume a greater air of permanence. At first each province was viewed as distinct and individually connected to Rome. In 171 вс, at the beginning of the Third Macedonian War, both consuls had hoped to be given command against Perseus, and the unsuccessful man had been sent with an army to the frontier with Illyria to protect colonists in the area. This man, Cassius Longinus, decided on his own initiative to march his army overland to Macedonia. By chance the Senate heard of his expedition and were able to send a commission to restrain him. On the one hand this is just another example of the Roman aristocracy’s lust for glory affecting their behaviour in the provinces, but it also shows that the Romans were beginning to conceive of their provinces as being linked to each other geographically. In the last decades of the century, the Romans mounted a series of campaigns to defeat the tribes of southern Gaul, creating the province of Transalpine Gaul (modern Provence) to provide a secure land route to their Spanish provinces. Gradually a coherent empire began to emerge from a collection of individual conquered peoples.