A History of Rome to 565 A. D.

by Arthur E. R. Boak

General characteristics. The chief characteristics of the military organization of the late empire were the complete separation of civil and military authority except in the person of the emperor, the sharp distinction between the mobile forces and the frontier garrisons, and the ever-increasing predominance of the barbarian element, not merely in the rank and file of the soldiers, but also among the officers of highest rank.

The limitanei. The troops composing the frontier garrisons were called limitanei, or borderers; also, when stationed along a river frontier, riparienses. They were the successors of the garrison army of the principate and were distributed among small fortified posts [pg 336](castella). To each of these garrisons there was assigned for purposes of cultivation a tract of land free from municipal authority. These lands were exempt from taxation, and, although they were not alienable, the right to occupy them passed from father to son with the obligation to military service. Thus the limitanei were practically a border militia. Their numbers were materially increased by Diocletian but reduced again by Constantine I who transferred their best units to the field army. The limitanei ranked below the field troops; their physical standards were lower, and their rewards at the end of their term of service inferior.

The palatini and comitatenses. To remedy the greatest weakness in the army of the principate, namely, its lack of mobility, Diocletian formed a permanent field force to accompany the emperor on his campaigns, for it was his intention that the emperors should personally lead their armies. Since the field troops thus formed the comitatus, or escort, of the emperor they received the name of comitatenses. Later certain units of the comitatenses were called palatini, or palace troops, a purely honorary distinction. The palatini and comitatenses were stationed at strategic points well within the frontiers.

Numbers. In both the garrison and field armies the old legion was broken up into smaller detachments, to each of which the name legion was given. They still continued to be recruited from Romans, but were regarded as inferior in caliber to the auxilia, the light infantry corps which were largely drawn from barbarian volunteers. A great number of new cavalry units were formed, so that the proportion of cavalry to infantry was largely increased. At the opening of the fifth century the troops stationed in Spain, in the Danubian provinces, in the Orient and in Egypt had a nominal strength of 554,500 of which 360,000 were limitanei and 194,500 field troops. However, it is extremely doubtful if the separate detachments were maintained at their full numbers. The scholarians, organized as an imperial bodyguard by Constantine I, numbered 3500. They were divided into seven companies called scholae, from the fact that a particular schola, or waiting hall in the palace, was assigned to each.

Recruitment. In the late empire the ranks of the Roman army stood open to all free men who possessed the requisite physical qualifications. Slaves were also enrolled from the fifth century onwards but their admission to military service brought them freedom. Recruits were either volunteers or conscripts. The universal liability [pg 337]to service existed until the time of Valentinian I, although in practice it was limited to the municipal plebs and the agricultural classes. Valentinian placed the obligation to furnish a specified number of recruits upon the landholders of certain provinces, and levied a corresponding monetary tax upon the other provinces. He also made it obligatory for the sons of soldiers to present themselves for service. Many barbarian peoples, settled within the empire, were likewise under an obligation to furnish a yearly number of recruits, who, however, were regarded as volunteers. Still voluntary recruitment was the rule under the late empire even more than under the principate, and the majority of the volunteers for military service were of barbarian origin. Corps of all sorts were named after barbarian peoples, and while barbarian officers received Roman citizenship, the rank and file remained aliens.

Discipline. The chief reason for the victories of the Roman armies of the early principate over their barbarian foes lay in their superior discipline and organization. And the burden of maintaining this discipline had rested upon the junior officers or centurions who came from the senatorial order of the Roman municipalities. By the end of the third century the centuriate had disappeared for lack of volunteers of this class and with its disappearance began a decline in discipline and training. The construction of the fortified camp was no longer required, the soldier’s heavy pack was discarded, and before the close of the fourth century the burdensome defensive armor was also given up. In equipment and tactics the Roman troops of the late empire were on a level with their barbarian opponents. Just as the Roman empire was unable to assimilate the barbarian settlers within its frontiers, so the Roman army proved unable to absorb the barbarian elements within its ranks.

Foederati. The decline in efficiency of the Roman troops and the confessed inability of the state to deal with its military obligations led to the taking into the Roman pay of warlike peoples along the Roman frontiers. Such peoples were called federated allies (foederati), and guaranteed to protect the territory of the empire in return for a stipulated remuneration in money or supplies. Such were the terms upon which the Goths were granted lands south of the Danube by Theodosius the Great. But in this case, as in others, it is hard to distinguish between subsidies paid to foederati and the payments made by many emperors to purchase immunity from invasion by [pg 338]dangerous neighbors. A danger inherent in the system was that the foederati might at any moment turn their arms against their employers. Retaining as they did their political autonomy and serving under their own chiefs, the foederati were not regarded as forming a part of the imperial forces.

The duces and the magistri militum. We have already referred to the complete separation of military and civil authority. This was carried out as far as the border troops were concerned by Diocletian. He divided the frontiers into military districts which corresponded to the provinces and placed the garrisons in each under an officer with the title of dux. The duces of highest rank were regularly known as comites (counts). Under Diocletian the praetorian prefects remained the highest military officers, and were in command of the field army. As we have seen, Constantine I deprived the praetorian prefecture of its military functions and appointed two new commanders-in-chief—the master of the foot (magister peditum) and the master of the horse (magister equitum). Under the successors of Constantine these offices were increased in number and the distinction between infantry and cavalry commands was abandoned. Consequently, the titles of master of the horse and master of the foot were altered to those of masters of horse and foot, masters of each service, or masters of the soldiers. In the East by the close of the fourth century there were two masters of the soldiers at Constantinople, each commanding half of the palatini in the vicinity of the capital, and three others commanding the comitatenses in the Orient, Thrace and Illyricum, respectively. In the West there were two masterships at the court, and a master of the horse in the diocese of Gaul.

But while in the East the several masters of the soldiers enjoyed independent commands, in the West by 395 A. D. there had developed a concentration of the supreme military power in the hands of one master, who united in his person the two masterships at the court. The master in Gaul, with the duces and comites in the provinces were under his orders. This subordination was emphasized by the fact that the heads of the office staff (principes) of the comites and duces were appointed by the master at the court. On the other hand, in the East, these principes were appointed by a civil official, the master of the offices, who was also charged with the inspection of the frontier defences, and from the opening of the fifth century exercised judicial [pg 339]authority over the duces. The latter, however, remained the military subordinates of the masters of the soldiers. Thus the concentration of military power in the West in the hands of a single commander-in-chief prepared the way for the rise of the king-makers of the fifth century, while the division of the higher command in the East prevented a single general from completely dominating the political situation.

Judicial status of the soldiers. Characteristic of the times was the removal of soldiers from the jurisdiction of the civil authority. In the fourth century they could only be prosecuted on criminal charges in the courts of their military commanders, and in the fifth century they were granted this privilege in civil cases also.