The Roman emperor Augustus (r. 31 BCE-14 CE) had extensive experience dealing with the men in the military, dating back to 44 BCE. He knew how to entice them and how to keep them happy, and he knew what displeased them. He had experienced enough mutinies to understand their causes. With this knowledge, he was able to implement wide-ranging reforms to the army. By 13 BCE, Augustus had created Rome’s first professional army. No longer would temporary armies be created to deal with temporary threats. Each of the 28 legions had 5,500 men plus cavalry reinforced by a similar number of auxiliary units. Altogether, there would be a permanent standing force of about 300,000 men. These men would serve for defined periods of time. Originally, the term called for 16 years of active service followed by four years in reserve. Those periods were extended in 6 CE to 20 and 5. The key to this system of enticing volunteers and keeping soldiers happy while performing a difficult job was, of course, money. During the republic, problems with money, including irregular pay, unfair or infrequent distribution of plunder, and dissatisfaction with discharge bonuses of cash and land, often led to mutiny.
Thanks in large part to the wealth of Egypt, Augustus was able to make significant economic improvements to military service. He provided pay of 900 sesterces, the same amount distributed by Caesar, which was itself a doubling of the previous stipend provided by the state. This pay would be distributed regularly and would not be subject to the whim of a general or the senatorial government. This was important be cause republican soldiers often did not receive pay in a timely fashion. Though the pay was not extravagant, the key to the system was the retirement benefits. Augustus provided either a cash bonus or land or both to men who had served their time. It seems that after 13 BCE, men received, instead of land, 12,000 sesterces, or about 12 years’ pay. Estimates vary, but possibly as many as 200,000 men received benefits during the first three decades of Augustus’s reign. These included mass discharges in 30-28 and 14 BCE. To cover all these expenditures, Augustus established the aerarium militare (military treasury) in 6 CE. To help fund this treasury, Augustus donated his own money and later imposed sales and inheritance taxes.
These economic reforms, at least for much of Augustus’s reign, helped keep the soldiers happy (or happy enough), removing one important cause of rebellion. The soldiers knew that if they remained loyal, the emperor and the state would provide for them. The soldiers now became defenders of the status quo. At least for the time being, mutinous officers could not use money as an incentive to spark a rebellion. At the same time the Augustan system was attempting to keep the men happy, it also encouraged divisions among the rank and file to prevent rebellion. The new, professional nature of the military led to a definite hierarchy among the regular soldiers.
Keeping the average soldier happy was only the first step. The second step involved the centurions. Thanks to his civil war experiences, Augustus realized the importance of the centurion in the chain of command. He had to do everything he could to bind these men closer to the state and to himself and at the same time worked to separate them in certain ways from the average soldier. Men became centurions on the basis of their military and leadership qualities, and certainly also of their loyalty to the regime. They inspired great respect among the men, unlike higher officers, who were often political appointees. As such, the centurions were crucial in a commander’s control of the camp and were the backbone of the army, vital for its continued discipline. They could act as an early warning system; since they were close to the men, they would know if any problems developed. Without their support, it would be nearly impossible for a commander to regain control and punish his men.
During the republic, the centurions did not always remain loyal to their commanders. Instead, they shared many of the grievances of the men and therefore often took a leadership role in these rebellions or remained neutral and allowed a mutiny to spread without acting to quell it or reporting it to superiors. Augustus’s system, in contrast, dramatically increased the status and wealth of the centurions through increased pay and retirement bonuses; it also increased their opportunities to rise up within the army and offered greater opportunities after discharge. Centurions’ pay was raised to between 5 times (for an ordinary centurion) and 20 times (for the primus pilus) the average soldier’s pay.
More money meant more separation between the centurion and the men, despite their similar origins. They also now had the opportunity to rise into the Praetorian Guard, which enjoyed better conditions of service in the capital and higher pay. They could rise through the ranks to become military tribunes or even camp prefects. The primus pilus was now granted equestrian status at discharge. This represented a huge opportunity for social mobility. No longer would a centurion join a mutiny and risk his future; he simply had too much to lose. The centurions were now in a privileged position and were therefore willing to defend Augustus’s government, which guaranteed their newfound wealth and status.
A chasm opened up between the centurions and their former comrades. Though he did rise from the ranks, a centurion would no longer feel the same strong kinship with the men. Conversely, the soldiers no longer believed that their centurions shared their views or grievances. Instead, many soldiers now disliked their centurions, not least because of their role as the camp disciplinarians. Augustus’s reforms, which included increased pay and discharge bonuses and numerous opportunities for social advancement, had successfully created a gulf between the men and the centurions, separating the centurions from the ranks from which they sprang while binding them to the princeps.
Augustus’s reforms were also designed to control his generals and officers. By 14 CE, there were nine military provinces in which legions were stationed. Because of Augustus’s greater imperium, all were subordinate and ultimately responsible to him, and none governed in his own right on his own independent authority. They were rarely allowed to remain in one place for any length of time. Instead, they were moved from province to province at the discretion of the princeps. The obvious purpose of this policy was to discourage the development of loyalty among a governor, his soldiers, and the provincials. Last, but definitely not least, these men were chosen not only for their competence but also for their reliability and their close relationships, sometimes very close, with Augustus and other members of the royal family.
The distribution and dispersion of legions and the proliferation of commanders and officers served Augustus’s purposes. There were so many commanders and so many subordinate officers that each could provide a check on the others; mutiny would be very difficult because numerous officers in numerous different camps would have to join an uprising to mount a credible threat, and with so many people involved in different locales, the chances of detection would be much greater. Commanding officers were no longer in a position to acquire the wealth and military glory independent of Augustus that could be used to challenge his authority or sap the loyalty of the men to him.
The Praetorian Guard represented another important element in Augustus’s efforts to control the army. Since 44 BCE, he had made use of elite units, not only the Praetorian Guard but also foreign cavalry, such as his German bodyguards. He knew how important these units were to maintaining control of his camp and protecting him against attack. It should be no surprise that he would keep these units once in control of the empire. The Praetorian Guard was raised to 9,000 men and stationed around central Italy. Guardsmen would be paid double the salary of the average soldier (1,800 sesterces rather than 900), would have shorter tours of duty (16 years active service followed by four years in reserve, rather than 20 and 5), and would be given nearly twice the retirement bonus (20,000 to 12,000 sesterces) and/or more land. The purpose of the imperial guards was the same as that of the republican guards: to protect the emperor and to help him control the other soldiers. Stationed in Italy, they would be entirely separate from the rest of the legions. This meant they would be unaffected by any mutinous movements in the frontier legions and then could be used by Augustus against rebellious troops. Despite their small numbers, these separate, loyal, elite units could be used to overawe regular legionnaires and to support a besieged general. The guards also allowed Augustus to control Rome and potential rivals in the capital. In short, they provided him with the necessary power to run the empire.
The building of forts was an important part of Roman military discipline: legions on campaign in hostile territory were expected to build fortified camps at the end of a day’s march to ensure their safety. The ancient historian Polybius has provided us with perhaps the best description of these marching camps. According to his account, such forts were rectangular in shape and were protected by both a ditch and a wall of wooden stakes. The tents within the camp were set up according to a regular pattern, which reflected the subdivisions of the Roman Army. This preset arrangement in turn helped ensure that Roman troops could erect their camps in as little time as possible. It has been suggested that the regularized layout of Roman forts may ultimately hearken back to the colonies, similarly built to a regular plan, that the Romans established as early as the fourth century BCE during the course of their expansion in Italy. A number of marching camps from the republican period have been excavated, although contrary to Polybius’s account some of them are polygonal rather than strictly rectangular in shape, showing that the Romans could alter the standard fort plan when they saw fit.
In general, however, Roman forts of the late republic and early empire continued to be rectangular in shape and standardized in the layout of interior buildings. The two most important buildings, located at the center of a typical fort, were the praetorium and principia. The praetorium was the residence of the fort’s commander, while the principia housed the standards and military shrine of the troops occupying the fort as well as administrative offices.
Roman forts of this period did not always take advantage of local topography like later medieval castles. The former were not meant to withstand long sieges by an enemy army but instead were intended to act as staging posts for Roman troops before they marched out and drove off the enemy. Over time, however, the Romans did make their forts defensible by, among other things, building them in stone instead of wood and by building larger projecting towers, with a wider field of vision, into the fort walls. Both of these developments began in the second century CE as the Romans sought to consolidate the territory they had conquered up to that point. Other examples of this consolidation include the elaborate fortified zones that the Romans built on the frontiers, most notably the Limes in Germany and Hadrian’s Wall in England.
In the later empire as the frontiers increasingly came under military threat, the design of Roman forts changed significantly. Forts of this period were built to be much more defensible and were designed to be able to withstand sieges until reinforcements could arrive. Late imperial Roman forts, unlike their predecessors, often were built on high points of land or other defensible topographical features and were often irregular in shape so as to take advantage of such features as much as possible.
Bibliography Chrissanthos, Stefan G. Warfare in the Ancient World: From the Bronze Age to the Fall of Rome. Westport, CT: Praeger, 2008. Goldsworthy, A. The Roman Army at War, 100 BC- 200 AD. Oxford: Oxford University Press, 1996. Sumi, G. S. Ceremony and Power. Ann Arbor: University of Michigan Press, 2005. Watson, G. R. The Roman Soldier. Ithaca, NY: Cornell University Press, 1969. Breeze, David J., and Brian Dobson. Hadrian’s Wall. New York: Penguin, 2000. Johnson, Anne. Roman Forts of the 1st and 2nd Centuries AD in Britain and the German Provinces. London: St. Martin’s, 1983. Miller, M. C., and James G. DeVoto, trans. Polybius and Pseudo-Hyginus: Fortifcation of the Roman Camp. Chicago Ridge, IL: Ares, 1994. Schönberger, H. “The Roman Frontier in Germany: An Archaeological Survey.” Journal of Roman Studies 59 (1969): 144-170.