Grand Strategy Of The Roman Empire (Part 3)
Luttwak’s third period, that of the late empire, is marked by a new type of defense that utilizes an even heavier fortified limes. According to Luttwak the Romans adopted a defense in depth strategy. The fortified systems of roads that linked the various garrisons were further strengthened with forts that provided supplies and men when needed. Watchtowers and sentry points provided light deterrence for small groups of enemies, forcing them to detour around such locations. Larger forces could not escape the notice of these scouts and observation posts. The early warning that these posts provided enabled Roman military to muster responses to larger threats and essentially engage enemy incursions from multiple angles. Luttwak explains the development of this system as a response to increased threats from a highly mobile enemy.
Sources from the period make note of the strengthening of the border during the late empire. Suidas writes of changes made by Diocletian. The zones near the frontier of the land are called eschatia, which are bounded by a mountain or the sea. … Again, Diocletian, when considering the state of the empire thought it necessary to strengthen all eschatia with sufficient forces and to build forts.
Procopius tells us that “In the past the Roman emperors stationed numerous soldiers everywhere in the frontier districts of the state in order to guard the frontiers of the empire.” This backs up the idea that the practice was well established before the reforms in the late empire. Benjamin Isaac challenges the notion of frontier fortifications, noting that the use of the term limes changes over time and in all the sources “there is in Latin no term to indicate what modern frontier studies describe as a limes, a defended border…In other words, there can be no justification for calling any chain of forts in a frontier area a limes.” Isaac also notes the fortification of cities as well as the garrisoning of legions inside urban centers during this period which he believes suggests that the army was unable to prevent major raids of the countryside.
What is clear from the sources is that over time Rome built a series of roads in the far reaches of its empires to connect various camps and supply locations. These networks of roads grew over time and contained watchtowers and guard posts. How these functioned is unclear. Luttwak believes that they are part of a defensive network while Isaac sees them as part of a system of control securing communication lines and trade lanes. There is evidence in the sources for increased construction and deployment of new legions into the Eastern part of the empire. What was the purpose of the additional legions and what function did they serve in the region.
The quest to understand Roman strategy as Mattern writes in Rome and the Enemy can be reduced in its base form to a desire to understand Roman behavior. (Mattern 1999: 22) She asserts that, “Frontiers were not chosen for strategic reasons, but rather congealed as a result of failure or non-military factors”. This view is shared by Isaac, Millar, and Whittaker. While all disagree with Luttwak’s interpretation that the limes and frontier areas were geared towards defense, they each reach different conclusions as to what the purposes were. Isaac in particular argues for an internal role for the legion. Both Tacitus and Josephus chronicle the use of Roman legions in suppressing internal rebellions. (Tacitus Hist. 5.12) (Josephus BJ. 5.1) Josephus also writes of Roman auxiliaries being utilized as a policing force, attacking bandits along Roman roads and launching punitive operations against gangs. Millar cites examples the legion engaged in pacification, occupation, and civilian administration of the provinces. Whittaker and Lee both highlight the role the Roman limes and frontiers played in concentrating and directing civilian and mercantile traffic through the provinces and border regions. Whittaker utilizes Hadrian’s Wall in Britain as a prime example of this. The various gatehouses along the wall served to force foot traffic through the areas that Romans wished and barred from areas that they did not want. This concept is important because it reinforces the notion of imperium or Roman control. Lee’s Information and Frontiers focuses on information and intelligence gathering in the Empire. He notes the use of these checkpoints along the roads and frontiers by Rome to gather intelligence from passing travelers and merchants, particularly against Parthia. Jerome, writing in 391, recounts the tale of one such traveler Malchus who was taken before the local tribune and questioned upon return from Arabia.
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