A Roman legion was much more than a collection of fighting men. The Roman people were great builders and engineers. A lot of this building was done by the army. Some building was for defence, like camps and forts, some for defence and usefulness, like roads and canals, some for the good of everyone, like aqueducts. Every legion did so much building that it always had skilled engineers with it wherever it went. But every ordinary soldier was expected to know something about building operations. Camps and forts were built most often. Every time an army on the march stopped for the night it built a camp. These camps were always constructed in the same way by every legion in all parts of the empire.
If a legion expected to stay in one place for some time it built a fort. Other forts were built at key points on the frontier, often near a ford or bridge, at a crossroads, near a mountain pass or harbour.
Some forts were much bigger than others. On the Emperor Hadrian’s wall, in northern England, some forts held twenty men, others over a thousand. In Trajan’s time a camp for two legions, situated on the outskirts of Alexandria, held around ten thousand men. Later in the empire’s history several double camps were built to house the defenders of the Danubian frontier.
Building a Fort
Forts were built of stone, camps of blocks of turf and timber. The methods of building were much the same.
The first job was to find a suitable site. It had to be near water, for drinking, and, if possible forts were built near streams for drainage. If the waterway could take boats then all the better. The site had to be in open country so that the defenders could not be taken by surprise. The Romans were very skilful at picking the best possible site for a fort.
Inside the fort everything was laid out according to a set pattern. Each fort had granaries and workshops. A supply base would also have a large workshop for making nails, tiles and pottery stamped with the legion’s name.
Barrack blocks were built for soldiers and their equipment. The outer room to store kit and equipment had to be large. All that men needed on active service would be stored there. This included a tent, millstones for grinding corn, armour and weapons for each man, together with his tools. Every legionary was issued with a saw, axe, sickle, chain, rope, spade and basket. His private possessions would be in the inner room by the straw mattress he slept on.
Headquarters was placed in the middle of the fort. The legion’s commanding officer and his staff worked at headquarters. They had clerks to help them. All the pay records and other documents of the legion were kept there. The camp temple, with the legion’s standards was also in the headquarters block.
Permanent sites had internal buildings that are relatively easily to distinguish from their ground plans. Barrack blocks, holding a century or turmae, were long and relatively thin buildings divided into accommodation blocks with a slightly larger block for the centurion (or decurion in an ala) at one end. The other rooms accommodated eight men, a contubernium, the same number as in the tents of a temporary camp.
Forts and fortresses had a centrally placed headquarters building and next to it in fortresses the house of the legate and his tribunes. The senior centurions of legions, those of the 1st cohort, also had houses. Granaries had characteristic thick and buttressed walls to hold the unit’s food. Most sites had workshops and legionary fortresses hospitals.