Rome: An Empire's Story (36 page)

Fig 16.
A detail of Trajan’s Column showing triumph of the emperor after the first campaign against the Dacians

Many of the core institutions of the Augustan empire built on the experiments of Caesar, Pompey, and even earlier generations. Alongside developments in taxation we can set the practice of extending the citizenship; a growing dependence on local elites to run their own communities; and the practice of using city-states as a basis for government, even in areas where they had never existed before. One way to describe the transformation of the empire at the turn of the millennium is to say that over a long period the Roman state experienced a tension between two divergent tendencies. The first we could label the pursuit for glory, the second the desire for security. A move in one direction made other moves that cohered with it more feasible, and so more likely. The disasters of the middle second and early first century
BC
—the Cimbric invasion, the Social and Mithridatic Wars, and the rise of the
populares
—had pushed the state a long way in the direction of security. Hegemony had been converted to empire, and new institutions developed to rule it. By contrast the accelerating competition between leaders from Sulla to Augustus pushed the empire towards the more risky pursuit of glory. After Actium security always trumped glory.

Perhaps this choice was never made consciously. Roman ideology certainly did not always reflect the new logic of empire. The idea that world conquest was a realistic and laudable aim was repeatedly restated, most influentially in the classroom, where it was encoded in the classics of Latin literature as defined in the last century
BC
. Imperial monuments and imperial ceremonial also reproduced the incidental music of a conquest state, long after it no longer suited the plot of Roman history.
²
But detailed investigation of the military system of the empire—investigations made possible by a wealth of epigraphic data—reveals a set of mutually supporting institutions that were well geared to preserving peace, and that consequently made further conquests difficult and costly. It has even been argued that the emperors made so much noise about conquest to compensate for their reduced willingness to attempt it.
³
Trajan was in some senses a throwback, a proof that an individual emperor need not be trapped by the role. Yet his reign, with its futile and short-lived conquests, is also a demonstration that expansion no longer suited the Roman Empire very well.

Augustus had offered an earlier object lesson when he decided on the conquest of Europe. Some historians have tried to excuse this on the grounds of geographical ignorance: maybe he did think the world was smaller than it was, or had no decent maps? None of this is believable. The diameter of the globe had been estimated two centuries earlier. Geographical
works of the day included descriptions of India and mentioned the distant silk people, the Chinese. Africa had been circumnavigated half a millennium before Augustus. Much more likely, Augustus’ European front was a tactical error driven by short-term political difficulties. A number of Augustus’ challengers in the 20s
BC
had been commanders of major provinces. Did he dare let someone else achieve victories in the Balkans or south Egypt? Besides, it was still unclear what Augustus’ own role in the state would be once he had restored civil peace. Triumphs for his heirs might help their succession plans too. External warfare was evidently still popular in Rome, although it is noticeable that from this point on fewer and fewer Italians fought in the legions. So Augustus fell back on the pursuit of glory when the logic of his situation demanded more efforts to create security. The poetry written in his court advertised future campaigns, promising conquests in Britain and Parthia, India and Scythia, while monumental art offered images of a world already conquered.
⁴

But where to start? Persia was a dangerous enemy which had defeated Crassus and humiliated Antony, and did not seem to want further conflict. The tribes of northern Europe must have seemed an easy option: Caesar had conquered all Gaul in only eight years with as many legions. Could Britain and Germany offer anything other than easy victories? At first the victories did seem easy, and the armies of Drusus and Tiberius rolled around the Alps, campaigned up to the Danube, and across the Rhine as far as the Elbe. But rapid progress was deceptive. Conquered Pannonia rebelled in
AD
6, and it took three years to restore order.

Almost immediately a Roman army of three legions was massacred in Germany in
AD
9. The Varian disaster—named after the general made to carry the can—was a trauma that echoed through the history and literature of the last years of Augustus’ reign. The astrologer Manilius used it as an example of the terrible catastrophes foretold by comets. The actual defeat was a running battle lasting several days: the site was recently located at Kalkriese near Osnabrück and has been painstakingly reconstructed. It cost the Roman army nearly 10 per cent of its manpower. All territory east of the Rhine was abandoned. A half-built Roman city has recently been found at Waldgirmes, offering eerie witness to the sudden change of direction. A great new province had been planned, and construction had begun on a network of civil communities just like that created in Gaul after Caesar’s conquest and in Pontus by Pompey. Roman accounts, reflecting the official line, blame Varus for behaving as if he was in a conquered
province, spending his time giving justice, imposing taxation, and dispersing his troops among native communities. But he was certainly following orders from the emperor. After disaster struck Rome pulled back to the Rhine, Waldgirmes was abandoned, and with it all the territory up to the Elbe. Conquest was never formally renounced, but it was not resumed in Augustus’ reign. Another imperial prince, Germanicus, visited the site of the disaster during the next reign but his campaigns were also—if less dramatically—unsuccessful. The north began to be quietly written off as ungovernable, poor, undesirable. Strabo, writing under the Emperor Tiberius, reported that Britain too would not pay the cost of its occupation.
⁵
Appian, a second-century historian, went so far as to claim alien nations had begged to be admitted to the empire, but the emperors had turned them down.
⁶
These were all lies.

For the emperors had much to gain from security, and there were easier routes to glory. Did Augustus ever realize that the real motor for the wars of Pompey and Caesar had been competition? And now there were no rivals. Emperors did not plan for peace, but they learned from their mistakes. The risks of failure never made up for the potential rewards offered by military expeditions. Much more could be achieved by diplomacy. And emperors soon found out how to massage the news from the frontier, playing up minor successes, suppressing news of reverses, claiming any victories for themselves, and blaming generals on the ground like Varus when things went badly wrong. The laziness of the Caesars was a very pragmatic response to the absence of rivals.

A World without History?

The choice of security over glory makes for unexciting history. Or so the senators of the imperial age affected to think. Court intrigues and imperial assassinations actually make for rather good drama. The histories written by the senators Tacitus and Dio, and the scandalous biographies of the courtier Suetonius and his late imperial successors, have inspired their share of racy novels and movies. But it is true that it is difficult to find a clear narrative in the political history of the first two centuries
AD
. Institutionally, culturally, and economically, there were slow changes.
⁷
The citizen body expanded and with it Roman law stretched over more and more of the empire’s subjects: that process of assimilation continued long after the Edict of Caracalla.
⁸
The greatest cities grew and acquired their complements of monuments. The rich grew richer, building great rural residences and endowing festivals, temples, theatres, and bathhouses in their native cities.
⁹
Trade flourished across the urban network, and between the great ecological divides into which the empire was divided. All these changes were real, but few were visible to contemporaries, and they were not the subject of history as the ancients understood it.

There were gradual changes in the style of imperial rule too. The monarchical nature of the emperors’ rule became more overt. As the emperors ruled from their itinerant courts they seem to have gradually developed a preference for direct over indirect control, and a greater reliance on state officials rather than aristocratic former magistrates. Augustus had travelled widely, but few of his first-century
AD
successors spent long away from Rome. The expeditions of Trajan and the restless travels of Hadrian were in some senses optional, and Antoninus Pius who reigned from 138 to 161 spent most of his time in Rome. The situation began to change with Marcus Aurelius, who succeeded him until his death in 180. Marcus and his co-emperor Lucius Verus (161–9), and then his son and successor Commodus, who ruled until his assassination in 192, were all compelled to spend long periods of their reigns on the frontiers. So did all the Severan emperors who ruled Rome between
AD
193 and 235. These necessary displacements were accompanied by the emergence of a new and more openly monarchical style. Away from senatorial sensibilities emperors could rule like the kings they had always been.

By the early fourth century there were up to four different courts at any one time, strung out along the northern and eastern frontiers of the empire. Wherever the courts rested for a few years—Trier or Antioch, Sirmium or Ravenna—magnificent palaces were created with great bathhouses, hippodromes, and reception areas. The empire came to be divided into four great prefectures, each headed by a praetorian prefect whose administration extended down into a growing number of provinces. Senators no longer played much part in the administration of the empire, and the Senate itself (or senates after Constantine created a second one in his new capital on the Bosporus) became peripheral to the political system. Ambassadors sought out emperors in the camps; law making had to be by edict rather than senatorial decree; consultation—even for form’s sake—was no longer practical. Emperors were away from Rome for years, and then decades. Constantius II, who with his brothers succeeded Constantine in 337, did not visit Rome
until
AD
357. Before that new order came about, however, the empire had to face a much more serious military emergency, one that in some senses lasted for two entire generations.

The Early Imperial Security System

Historians sometimes write of Rome as having a Grand Strategy,
¹⁰
but there is no real sign that any such thing was ever planned or implemented. The deployment of the legions was accidental, the evolving product of incremental changes made in response to immediate needs. When expansion ended, Augustus’ campaigning armies had stopped in their tracks. Troops would be moved for imperial expeditions like Claudius’ invasion of Britain, or if they were needed to crush a rebellion or participate in a civil war. Over time the legions gravitated to the points of stress. Spain was far from the frontiers and relatively peaceful, and as a result the size of its garrison was progressively reduced. On the Danube and in the east troop numbers increased slightly, but always limited by the salary bill. The emperors knew where the troops were, how many they were, and what they were owed. But there is no sign they made use of this information to plan for anything but the short term.
¹¹

It is not always clear exactly where the armies were deployed in the early years of Augustus’ reign, except that they were kept out of Italy, where only the Praetorian Guard—made loyal through extra pay—were allowed in the capital. But a decade into Tiberius’ reign we happen to have a snapshot, from a passage in Tacitus’
Annales
, of the locations of what were now twenty-five legions.
¹²
They were concentrated overwhelmingly on the northern and eastern frontiers: facing across the Rhine and Danube, that is, and stationed along the long frontier with Parthia and its vassals. Only token forces remained in Spain, Africa, and Egypt. Many other provinces were effectively unarmed. Legions of heavy armed infantry formed the core of the early imperial army. They resembled the Republican armies in terms of their equipment and battlefield tactics. Auxiliary units of cavalry, light infantry, missile troops supported them, alongside teams of engineers and other specialists. There were naval bases in the Mediterranean, and in time fleets were established on the major rivers. That pattern stayed more or less unchanged until the middle of the third century, although the number of legions increased to thirty-three and some were moved to newly conquered regions
like southern Britain and Dacia. The total strength was always very small. At its height the early imperial army numbered less than 200,000 legionaries and perhaps as many support troops, to protect and control an empire of between 50 and 100 million inhabitants.

Keeping the army small was a financial necessity given the huge share of the imperial budget it consumed. This meant it had to be highly efficient. The campaigning armies of the late Republic and the reign of Augustus had marched and camped in strength, but a different disposition was needed for their new roles. The logic of the imperial frontiers was all based on establishing a communications advantage over its opponents. Little by little the frontiers became a dense network of bases—some very small—signal stations, barriers, control points, and, most important of all, roads. Hadrian’s Wall provides an excellent example of the kind of system that developed in the second century, but the ditches and ramparts that so impress us today were among the latest and least vital components of a frontier system. A precious collection of letters from Vindolanda reveals the collection and processing of information on what was happening beyond the frontier; the management of provisioning; the constant redeployments of soldiers along the frontier; and communications back into the province.
¹³
Signal stations ran down the coasts watching for raids by sea. Groups of scouts operated far north of the wall, and local leaders were cultivated with gifts that Romans called subsidies. A slightly different system of signal stations and forts passed news on barbarian movements up and down the upper German
Limes
, and in the pre-desert of North Africa military installations were different again. Physically the frontiers developed in a piecemeal way, adapting to local circumstances not a central model, but the guiding logic was the same.