As with any large empire that is continuously expanding, the most important area to maintain and control is its boundaries, without full control of its borders it is impossible to continue the expansion processes. The Roman Army was incredibly good at conquering its opponents using both its superior maneuverability and discipline. However, when it came to occupying and maintaining its borders after conquest the Roman Empire lacked a centralized operation which led to mismanagement of the newly acquired territory (Mann, 514).
Starting with Augutus, the emperors of Rome during its expansionary period often times attempted to control territory right up to the river front which was difficult to do since the Roman Army was strictly a land-based army and struggled to hold its position along river fronts such as the Danube and the Rhine. It can be seen that, for mostly political reasons, the frontiers of the Roman Empire were maintained at noticeable places. For example, it was very important that each emperor controlled the river-front of the Danube and the Rhine because it marked a clearly defined line for which the Roman Empire ended and the savage lands began. It built confidence in the Roman community and often times helped the current emperor gain popularity among the Roman citizens (Mann, 513).
In the fourth century, new mobile armies were created which slightly improved the effectiveness of the frontier forces with proper training which enabled the forces to re-form strung out troops along the frontier into small mobile forces at a predetermined assembly point (Mann, 513). This made for a sturdier defense network in case there was an attack on the border. However, it can be seen that although the frontier forces were being trained well they would ultimately fail. Eventually new mobile armies were put in their place and the frontier forces were downgraded to second-rate troops. Their military value fell until they were essentially only used as border police (Mann, 517).
Progression of the Roman Empire (0:23 – 0:37)
Emperors had three main ways of communicating with their leaders who were maintaining the borders of the Roman Empire. The first was by sending men on missions to pass along the frontiers gather new information and report back. The second way the emperor gathered information was through the many reports sent to him periodically by the governors closest to the Empire’s boundaries. Lastly, he learned of new information from the arrival of foreign envoys. Unfortunately, each source of information gave him a distorted update of the frontiers because each source was concerned about their own interests and not about the interests of the emperor. This made for an inefficient communication stream and did nothing to aid the already poorly managed frontier forces (Millar, 3).
As the Roman Empire grew into a major world power, we would expect that such a large world power would have some of them most advanced communication systems seen in the world at that time. However, as stated earlier, the communication lines between the frontiers and the emperor were very distorted and inefficient. Naturally, as an empire grows in size the distance that is traveled by a messenger from frontier lines to the mainland stretches in length. It seems obvious that as an emperor the communication with the exterior of your empire would be paramount. If this was the case perhaps we would see evidence of communication networks across the ancient Roman Empire. However, we don’t. In fact there is no found evidence that suggests the Empire possessed any long-distance signaling procedure at all. If the emperor in fact set up relay teams of messengers, it must not have lasted very long. A less expensive, slower method was soon adopted which involved only one messenger who traveled the entire distance with the information. This method caused a lot of variability and was very unreliable. The time it took for the message to be sent and received was not only dependent on the resilience of that single messenger but also on the efficiency and reliability of the people supplying the horses along the journey (Millar, 10). This added to the communication disaster that was the Roman Frontier and certainly played a large part in the mismanagement and lack of knowledge shared across the vast Roman Empire.
(image source: http://jacksonbbrown.com/ss/wp-content/uploads/2012/08/purple_romanempire_map.jpg)
Roman expansionism was influenced, in part, by the borders of the empire. Rome tried to maintain natural borders like mountain ranges or rivers. Lacking these, they did not simply draw an arbitrary line to mark their borders, but rather used a frontier guarded by members of the army, who effectively acted as a police force on border patrol. In certain cases, when these methods were not enough, they did create border markings, such as the Hadrian’s Wall in Britain. (Wheeler, 11)
In the East, however, not as many of these natural borders existed. Because of this, the Empire was forced to set up defensive encampments, mostly in cities along the border, to act as a barrier. In addition, major bands of troops have been found to have fortified positions on highways that align with the borders of the empire. This suggests that the empire recognized the threat of outside forces such as the Arabs and Persians (Wheeler, 38).
Since there do not seem to be any firm boundary lines, the purpose of creating borders does not seem to be to split the Romans off from all others, but rather as a security measure aimed at protecting the internal empire against large invading forces. Some of the natural barriers, such as mountain ranges, created a natural funnel for defense. In these cases, the Romans stationed a force at the near end of these funnels. The point of using a frontier as a border is also strategic. Since open expanses were the best place to stage an attacking army, the Romans built defensive forts in these open spaces. The forts served a dual purpose of breaking up the open frontiers, as well as having a well-defended base from which to defeat the enemy.