Rome: An Empire's Story (37 page)

The vast majority of military units were based on the frontiers. Yet soldiers were ubiquitous in the empire. Detachments provided protection for provincial governors and procurators, for messengers and tax collectors, for movements of grain and cash, for the managers of imperial mines and quarries with their workforces of slaves and criminals, and for the authorities of the larger, more unsettled cities. Centurions in particular acquired a whole range of functions we do not normally associate with the military. They acted as district officers in the northern provinces, can be found on detachment organizing provisioning and as the most recognizable representatives of Roman government depicted in the New Testament. Particularly trusted soldiers served as
beneficiarii consulares
, effectively
aides de camp
to governors. The early empire had no civil service, and there were some jobs that it was impolitic to entrust to imperial slaves and freedmen.

Fig 17.
Hadrian’s Wall

Imperial propaganda proclaimed that the soldiers protected the provinces. That picture is only half true. The legions were also the emperors’ ultimate weapon against both provincial rebellions and aristocratic usurpers.
¹⁴
The mass demobilization of Roman soldiers at the end of the Triumviral period had been driven by financial and political priorities. Armies were dangerous, unpaid ones doubly so. Now they would be composed of career soldiers who served for twenty or more years, loyal to the emperors, not their commanders.
¹⁵
On retirement the emperors provided each man with a substantial bonus, so long as he had proved himself loyal. Commanders,
drawn from the senatorial and equestrian orders, came and went. It was the centurions, risen from the ranks, who provided continuity of command and military expertise. Ceremonial was deployed to bind the soldiers to the imperial family. Army units celebrated imperial birthdays, and worshipped the emperors along with the
signa
, their standards. A third-century calendar from the eastern frontier post of Dura lists endless holidays marking the anniversaries of imperial family members, some long dead. Emperors and their sons took care to visit the legions, and even commanded them when it was safe to do so.

Mostly the system worked. Civil wars only broke out in 68 and 196 when entire dynasties had been extinguished. A few rebellious generals discovered to their cost the depth of loyalty the legions felt to the imperial family of the day.
¹⁶
That loyalty meant that the legions could also be deployed against provincial rebels. During
AD
69 the legions of the Rhineland were deployed first against Vindex, a senator from southern Gaul who had rebelled against Nero, and then against the Batavians of the lower Rhine who had tried to use the Roman civil war that followed his death as an opportunity to secede. The legions were in principle recruited from Roman citizens, but Italians rarely joined up after Augustus’ reign. The main sources of recruits were first the Roman cities of the inner provinces and later the camps themselves. One sign of the success of the emperors’ investment in maintaining the loyalty of the troops (and perhaps too of the socialization effects of long service) is that legions almost never made common cause with neighbouring provincial populations. Troops recruited in Gaul and Germany were content to be deployed against British, Gallic, and German rebels, and the army of Numidia to march against African usurpers.
¹⁷

Mostly, however, the soldiers inhabited a world of their own. The larger camps of northern Britain, the Rhineland, the Danube provinces, and Africa eventually came to resemble cities, equipped with monumental walls and gates, stone-built amphitheatres, bathhouses, and shrines. Formally soldiers could not marry and camps were organized in barrack blocks arranged in precise parallel lines, but the artefacts and clothes found in them shows there were women and children in these communities too, as well as in the informal villages called
canabae
that grew up alongside them. In Syria and Egypt soldiers mostly lived in cities in any case. Documents from Dura show them marrying and buying land and in general assuming the sort of roles in local communities that their relatively good pay and excellent connections could secure them.
¹⁸

The Roman Empire had no Grand Strategy, but it nevertheless developed a frontier system quite like those of many other tributary empires. The most common point of comparison is China’s Inner Asian Frontier, the limit between the areas controlled directly by Chinese officials and a great periphery within which subject nations shaded out into barbarian allies and enemies.
¹⁹
China, like Rome, enjoyed some technological advantages over its neighbours, although in some periods there was something of an arms race as China sought to prevent technology transfers to the barbarians. China, like Rome, was able to provision and supply its troops from an intensely farmed and taxed hinterland. The Chinese too deployed a mixture of linear barriers and garrisons of regular soldiers with irregular allies, and they too sought an information advantage over their opponents. The information system extended deep into the provinces, to the imperial court or courts. It was not Grand Strategy that preserved either empire, but the tactical advantages given by information superiority.

Map 5.
The third-century crisis

Crisis on the Frontiers

The Roman system had, naturally, its weaknesses too. One consequence of depending on an infantry army based at the edge of empire was that it was slow to respond to disasters in the interior. Roman troops were generally successful against provincial rebellions during the first two centuries
AD
because most rebellions occurred relatively near the frontiers, and the rebels were usually stationary and had no fortifications. Order was generally restored within months. The Jewish war lasted as long as it did because the Jews possessed fortresses. Another problem was that more mobile enemies, once they broke through the frontier, could outrun Roman armies. When the frontiers did collapse, as they did in the third century, and raiding parties penetrated as far as Athens and Ephesus and Tarragona, they found rich cities with no defenders and often no functioning defensive walls. Civic populations learned the lesson. During the late third and fourth centuries, city after city built defensive circuits, sometimes dismantling earlier monuments to create safe zones in the middle of once extensive cities. One third-century emperor, Aurelian, actually built walls around the centre of the city of Rome. One of his predecessors, Gallienus, had also begun developing a more mobile army, one based on cavalry, which could act as a rapid response force. The use of troops of this kind, alongside the legions, became more and more evident in the changed conditions of war on the northern frontier. Constantine too was credited with an enlargement of their role. Meanwhile, at the eastern end of empire Romans and Persians were both developing armies based on heavy
cavalry. Where urban fortifications were also improving as fast as techniques of siege warfare, the military landscape came to look more and more medieval, a world of knights and castles amidst a landscape of peasant villagers.

The gradual social and economic transformations of the first three centuries
AD
were not confined within the political limits of the empire. The political economy of the empire may be thought of as a vast redistributive system that drew resources from all over the interior and spent them at the frontiers, mostly as army pay. The court was the other main recipient and this too was increasingly located at the edge rather than the geographical centre of the empire. Perhaps no provincial societies were transformed as utterly as those on the frontiers. The effects can be traced in the spread of new cults, of epigraphy and technology, and in the apparent prosperity of areas that had once been marginal. Nor were these effects confined to Roman subjects. The eastern frontier bisected a chain of caravan cities with ancient shared traditions of language, cult, and commerce. Greek, Aramaic, and its sister languages were spoken in a great arch that stretched from the Mediterranean to the Persian Gulf. By the late third century there were populations of Jews, Christians, and Manichaeans on both sides of the Romano-Persian frontier.

Rome’s northern frontier had bisected other peoples with shared prehistoric cultures. The existence of a frontier zone promoted connections. Population densities were low in this region, relative to the Mediterranean world, and there were no cities beyond the Roman provinces. But the agricultural potential was high. Commerce, including slaving, crossed the frontier, and there is archaeological evidence for Roman manufactures in a broad band 50–100 kilometres (around 30–60 miles) wide stretching back from the frontier.
²⁰
There were technology transfers too. The political units and ethnic groups of this zone seem to have been quite unstable. Roman writers sometimes blamed this on differences of temperament and characterized barbarism as a deficiency in the stability of settled, urban societies. Perhaps the larger hegemonies were intrinsically temporary. Yet these populations were not nomadic, and it is possible their political fragmentation was actively managed by Rome, which (like China) gave subsidies to their friends, took hostages, sheltered exiled princes, and generally tried to extend their control well beyond the limit of the provinces. Periodic raids and expeditions by both sides were simply one part of a complex relationship. From early in the first century
AD
there is also evidence for the recruitment of ‘barbarians’ to serve in the Roman army, and some rose to high ranks. Romans often found themselves facing enemy armies commanded by former Roman soldiers, like Arminius who had led the massacre of Varus’ legions in
AD
9, in fact, and
many spoke Latin. By the second century, many societies bordering the Roman frontier were locked into a series of interdependent relationships with Roman power. Certainly the leaders of the groups we hear of in the third century, such as the Alamanni on the upper Rhine, and the Goths on the lower Danube, knew the Roman Empire well.
²¹

That world began to change in the late second century
AD
for reasons that are fiercely disputed. One school of thought sees the transformation of barbarian societies as the main cause of the collapse of the frontiers. The long relationship with Rome created better organized and equipped enemies who knew very well the riches the empire had to offer. Eventually Rome lost the arms race and the frontiers folded. Others see the change originating in Rome’s increasing military commitment on the eastern front. As troops were withdrawn from the west to serve first against Persia, and then in successive civil wars, the delicate balance on the western frontiers collapsed: Alamanni, Franks, and others walked into provinces that were effectively undefended. Yet others see the origin of the crisis in obscure movements on the distant Steppe, where truly nomadic peoples, especially those that Romans later came to know as the Huns, pressed hard on the settled barbarians of temperate Europe pushing some populations, like the Goths, south and west onto the Roman frontiers. Large population movements certainly occurred within Europe in some periods, and had intruded into Mediterranean world on several occasions, including the Gallic sacks of Rome and Delphi in the fourth and third centuries
BC
and the Cimbric wars and the Helvetian migration at the end of the Republic. Various combinations of all these factors might, naturally, be imagined. The problem is simply that we know very little of movements so far beyond the Roman frontier.

One traditional narrative of the crisis begins in the late second century
AD
with Marcus Aurelius’ wars against the Marcomanni and Sarmatians, wars that kept him occupied for years on the northern frontier. The new provinces he allegedly contemplated creating would have been to the west of the three Dacian provinces founded by Trajan earlier in the century. But unlike Trajan’s wars, these did not result from an imperial initiative. The Marcomannic Wars began with a German invasion of Italy in 166 and continued, with only short periods of remission, until 175. A new war drew Marcus back in 177 and he was still campaigning on his death in 180. Commodus abandoned the war rather than finishing it. The frontier evidently held, even while Roman armies were distracted by civil wars in the 190s. Renewed activity on the northern frontier began on the Danube in the 230s with raids on Black Sea vassals of Rome and then on the Roman
province of Moesia. Gothic warbands raided Dacia and the Danube provinces in the 240s. Decius, who ruled between 249 and 252, briefly repelled them, but was killed in a counterattack. Goths continued to raid through the 250s. Who were these groups, not yet united into a single force or nation? One possibility is that the Goths originated among populations who had lived on the borders of Trajan’s new Dacian provinces, peoples who had recently undergone processes of social transformation of the kind experienced by other German-speaking groups on the Rhine much earlier.
²²
Whether wars on the lower Danube led to Roman neglect of points further west, or whether now-invisible pressures moved east to west over the century, the security crisis spread. On the middle Danube, the Sarmatians raided Noricum, Rhaetia, and Pannonia in the later 250s. At the same time there were raids by the Alamanni across the Rhine into Gaul and down into Spain. During the 260s Tarraco was sacked by the Franks, Athens by the Heruli, and Ephesus by the Goths. The Roman recovery began finally in 268 when Claudius II defeated the Goths at Naissos: thereafter it was surprisingly fast. Aurelian expelled the Iuthungi from Italy in the early 270s and Probus repelled the last major invasion of Gaul across the Rhine in 276.