2.16 The Empire
By the year 117 CE under Trajan, the Empire reached its greatest size. It encompassed most of England across to Germany and Romania, all of North Africa from present-day Morocco, and extended to the borders of the Parthian Empire. Beyond these borders were “barbarians” of various kinds; as far as the Romans were concerned there were no civilized people outside of their borders except the Persians. Trajan’s successor, the emperor Hadrian, built an enormous series of fortifications to consolidate power on the frontiers – these were eventually permanent garrisons and fortresses that were meant to serve as barriers to prevent “barbarian” incursions. Some of these survive to the present, including Hadrian’s Wall in northern England. While fleets patrolled the rivers and oceans, these garrisons controlled access to the empire.
As far as the Romans were concerned, there were only two things beyond those borders: to the north and northeast, endless tracts of inhospitable land and semi-human barbarians, and to the east, the only other civilization Rome was prepared to recognize: the Persians. For the rest of the Roman Imperial period, Rome and Persia periodically engaged in both raiding and full-scale warfare, with neither side proving capable of conclusively defeating the other. The closest Rome came to defeating the Persians was under Trajan when he managed to conquer Armenia and parts of Mesopotamia, but after his death Rome swiftly abandoned those territories. Even as they fought, however, Persia and Rome still traded, and Rome also adopted various Persian technologies and military tactics (for example, Rome adopted irrigation techniques from Persia, and Persia adopted engineering techniques from Rome). Persia had the best heavy cavalry in the world, and Rome learned to add heavy cavalry units to its legions by the fourth century CE.
Far beyond Persia was the Chinese Empire, already thousands of years old. China and Rome never established formal diplomatic ties, although the leaders of both empires knew of one another. During the entire period of Roman Imperial power, only China could produce silk, which was highly coveted in Rome. Shipments of silk moved along the aptly-named Silk Road across Central Asia, directly linking the two most powerful empires in the world at the time.
In addition, a major navigational breakthrough occurred during the time of Augustus, when the Romans learned to navigate the Indian Ocean using the Monsoon winds to reach western India. There, they could trade for Chinese silk at much better prices. This journey was hugely risky, but if a Roman merchant could pull it off and return to Rome with a cargo hold full of silk, he would earn fully 100 times his investment as profit. Along with spices, especially pepper, the trade for silk eventually drained enormous amounts of gold from Rome, something that added up to a serious economic liability over the hundreds of years of exchange.
The most important, and threatening, border for Rome was to its north, on the eastern and northern banks of the Rhine and Danube rivers. The region the Romans called Germania was an enormous stretch of heavily forested land, which was cold, wet, and uninviting from the Roman perspective. The German barbarians were a hugely diverse group of tribes practicing feudal law, the system of law in which offenses were met with clan-based violent retribution or blood payments. For hundreds of years there were complex relationships between various tribes and the Roman empire in which the Romans both fought with and, increasingly, hired German tribes to serve as mercenaries. Eventually, some of the Germanic tribes were allowed to settle along the Roman borders in return for payments of tribute to Rome.
The two major rivers, the Rhine and the Danube, were the key dividing lines to the north of Rome, with Roman legions manning permanent fortifications there. As far as the Romans were concerned, even if they were able to militarily they did not want to conquer German territory. The Romans tended to regard the barbarians as being semi-human at best, incapable of understanding true civilization. Some Romans did admire their bravery and codes of honor – Tacitus contrasted the supposed weakness and dissolution of his contemporary Romans with the rough virtue of the barbarians. That being noted, most Romans believed that the Celts, conquered by Caesar centuries earlier, were able to learn and assimilate to Roman culture, but the Germans, supposedly, were not. Likewise, Germania was assumed to be too cold, too wet, and too infertile to support organized farming and settlement. Thus, the role of the walls was to hold the barbarians back rather than to stage new wars of conquest. For about three hundred years, they did just that, until the borders started breaking down by the third century CE.
The Army and Assimilation
Rome had established control over its vast territory thanks to the strength of the citizen-soldiers of the Republic. As described in the last chapter, however, the republican military system declined after the Punic Wars as the number of free, economically independent Roman citizens capable of serving in the army diminished. By the first century, most Roman soldiers became career soldiers loyal to a specific general who promised tangible rewards rather than volunteers who served only in a given campaign and then returned home to their farms.
Perhaps the most important thing Augustus did besides establishing the principate itself was to reorganize the Roman legions. He created a standing professional army with regular pay and retirement benefits, permanently ending the reliance on the volunteer citizen – soldiers that had fought for Rome under the republic. Instead, during the empire, Legionaries served for twenty years and then were put on reserve for another five, although more than half died before reaching retirement age. The major benefits of service were a very large bonus paid on retirement (equivalent to 13 years of pay!) and land: military colonies spread across the empire ensured that a loyal soldier could expect to found a prosperous family line if he lived that long. Service in the army was grueling and intense. Roman soldiers were expected to be able to march over 20 miles in a standard day’s march carrying a heavy pack. They were subject to brutal discipline, up to and including summary execution if they were judged to have been derelict in their duties – one of the worst was falling asleep on guard duty, punishable by being beaten to death by one’s fellow soldiers. Roman soldiers were held to the highest standards of unit cohesion, and their combat drills meant they were constantly ready for battle.
Starting in the Augustan period, the essential division in the Roman military was the legion, a self-sufficient army unto itself that could be combined with other legions to form a full-scale invasion force but could also operate on its own. Each legion was self-sufficient as it traveled and could be expected to operate within hostile territory for long periods if necessary. Each legion was led by a legate, usually a powerful noble appointed by the imperial government or the emperor himself. These legates were often politicians rather than soldiers, meaning that the key figures in actual battle were the centurions, each of whom had earned his position through exemplary service. Perhaps most important of all was the lead centurion, the First Spear, who dictated tactics on the field.
The legions were made up of Roman citizens, but not all members of the Roman military were citizens. Instead, as numerous as the legions were auxiliaries: Roman subjects who served the empire. As of 23 CE the auxiliaries numbered about 150,000 men, which was the same as the legions at the time. The emperor Claudius rewarded 25 years of service with citizenship; by the early second century, all auxiliaries gained citizenship on discharge.
A key legion that stood apart from the rest of the military was the Praetorian Guard, whose major job was defending the emperor himself, followed in priority by the defense of Italy and the city of Rome. The terms of service in the Praetorian Guard were very attractive: 16 years instead of 25 and pay that was significantly higher (this was a necessity: emperors started with Claudius knew that they were vulnerable to the Praetorians and needed to keep them happy and loyal). Not surprisingly, Praetorians were recruited from veteran legionaries. They did not simply serve the emperor in the city of Rome, instead actively campaigning both when defending Roman territory from invasion, and with the emperor while on campaign.
The army was important in integrating provincial subjects into Roman culture. Military families were a reality everywhere, with sons often becoming soldiers after their fathers. Thus, the experience of serving in the legions or the auxiliaries tended to promote a shared sense of Roman identity, even when soldiers were drawn from areas that had been conquered by Rome in the recent past. In the provinces, there was a pattern that took place over a few generations. After being conquered by the Romans, there were often resistance movements and rebellions. Those were put down with overwhelming and brutal force, often worse than that of the initial invasion. Eventually, local elites were integrated in the governor’s office and ambitious people made sure their sons learned Latin. Locals started joining the army and, if lucky, returned eventually with money and land to show for it. Roman amenities like aqueducts and baths were built and roads linked the province with the rest of the empire. In short, assimilation happened. A few generations after Roman conquest, many (local elites especially) in a given province would identify with Roman civilization. Regular people in the countryside, meanwhile, would at least be obliged to tolerate Roman rule even if they did not embrace it.
