Roman Fort

Roman Fort, fortified enclosure designed to provide permanent accommodation for the military garrisons which were involved in the conquest and administration of the Roman Empire. The forts of the Roman army comprise some of the most familiar remains of the Roman world and may be found in most parts of Europe, North Africa, and the Middle East. They should be distinguished from other military sites to which they bear some resemblance: these are the legionary fortresses, larger in scale and conception and designed to accommodate a full legion, and the marching camps, which were temporary structures intended for the shelter of troops on campaign.

The form of the permanent Roman fort developed from the temporary military camp during the late Republic, at the beginning of Rome's greatest period of expansion. Early forts are known along the upper Rhine, dating from the campaigns of Augustus during the late 1st century bc. The design of the fort soon became standardized: variations in layout are usually due to occupation by different types of military unit. Forts are typically sited to control strategic positions at, for example, major road junctions or river crossings, or are distributed along frontiers (as in the case of the concentration of forts along Hadrian's Wall). Their major functions were the policing of the unruly populations of conquered territory and, as the empire came increasingly under pressure from outside, the defence of Roman lands against barbarian invaders.

The typical fort was designed to hold either 500 or 1,000 auxiliary troops: they are termed, respectively, “quingenary” and “milliary” forts. The plan is almost invariably rectangular, with characteristic rounded corners which give the fort the form of a playing-card. The construction of early forts was often of timber, with a rampart of earth or stacked turf. These early timber forts were often rebuilt in stone, and by the 2nd century most new forts were sturdy masonry constructions.

The main elements of a fort's defences were a ditch, either V-shaped or with a vertical outer edge (a “Punic” ditch), and a rampart, usually faced by a stone wall. There was a strongly defended gate in each of the four sides, and often towers at the corners and at intervals along the four main wall faces: in the later Empire these towers were often built as bastions projecting from the wall face, and were designed to house the artillery, which was becoming increasingly important in the face of pressure on manpower.

The internal layout of a fort regularly followed a fairly standard plan. In the centre was the principia, or headquarters building: this was the administrative heart of the fort. It also included a strongroom, in which the regimental cash was kept, and a shrine dedicated to the cult of the Emperor, which also housed the regimental standards and battle-honours. This building commanded the junction of the two main streets (via principalis and via praetoria) that traversed the fort. Adjacent to the headquarters was the praetorium, which acted as the quarters of the commanding officer and as accommodation for official visitors. In the later Empire, this commandant's house could assume lavish proportions and take up a large part of the fort's interior. An important feature of a fort was at least one granary or storehouse. This held supplies for the garrison, and sometimes for horses too: it is easily recognized by its raised and ventilated floor, intended to protect stores from damp and from vermin. Most of the remainder of the fort's interior would be occupied by barrack blocks and, if it were a cavalry unit, by stables.

The bathhouse with which each fort was provided was usually sited outside the rampart, and near a stream. Elaborate, multi-seater latrines are also a feature of some forts. Also outside the fort would usually be found a parade-ground for martial exercise and for the numerous ceremonies that punctuated Roman military life: this needed to be no more than a levelled space, with a raised tribunal or “saluting-platform” at one end. In many cases, also, the area around the fort would include a civil settlement—the vicus—carefully laid out with shops and buildings in Roman style, occupied by native craftsmen and traders. This is a reminder that Roman forts were not seen merely as military facilities, but also as the main influence through which native populations could be introduced to the benefits of Roman civilization: over much of the empire, the Roman fort would be the most impressive structure that anyone had ever seen.

In Britain, the best-preserved Roman forts are to be seen in the military zone of the northern frontier: perhaps the most complete is that at Housesteads, on Hadrian's Wall, although other wall forts at Chesters, Vindolanda, and Birdoswald have also been largely excavated and are accessible to the public.