This war will support itself
Cato the Elder instructs his men to take what they need
The impact of the Roman army on the environment was gigantic, at least by the standards of the ancient world. The construction of forts and fortifications was only the start. Peacetime activities also included participation in significant mining and engineering projects, often involving soldiers in supervision and management.
The arrival of the Roman army in a frontier zone, especially a temperate area where trees were widely available, automatically resulted in colossal quantities being felled and prepared. Clearance must have been undertaken on a grand scale. Each turf and timber fort required vast amounts of wood for building and maintenance; felling and transporting it was a task so arduous that it helped provoke a mutiny in AD 14 amongst the forces in Germany. The army also required wood for day-to-day heating, cooking and metalworking. The military extraction of iron ore in the Weald of south-east Britain, for example, meant there was a constant and huge demand for charcoal for the smelting furnaces.
When Agricola’s legionary fortress at Inchtuthil in Scotland was abandoned and cleared away c. 87, around 900,000 iron nails of various sizes that had been prepared for the fort were buried in a pit 12 ft (3.66 m) deep to prevent the local tribes from reusing them for weapons. Pottery and glassware were smashed up and buried, but evidently melting down the nails and taking the iron away was thought too much trouble. They bear witness to the effort and logistics involved in mining, smelting and working the iron, as well as transporting it to the site either in pigs or as finished products. This kind of usage meant long-term management – the constant rotation of areas of woodland, making usable timber available within a reasonable distance rather than operating on a slash-and-burn basis, which was fine for conquest but hopeless for permanent garrisons. The legionary fortress of Caerleon may have required 370 acres (150 ha) of woodland to supply enough timber for the initial construction alone, and more for maintenance. A unique wooden writing tablet found at the fortress in a context dated to c. 75–85 seems to mention the collection of materia, ‘building timber’. A squared beam found in a Roman quay in London had a branded inscription of a cohort or ala of Thracians which had probably been responsible for felling it; the beam had perhaps been reused from a military building. An inscription from the Rhineland, dated to 214, records that a vexillation of Legio XXII Primigenia was involved in the gathering of timber. Although the Romans made some use of coal, they seem primarily to have relied on timber for furnaces. Estimates based on the small private bath-house at Welwyn suggest that a 58 acre (23 ha) area of managed woodland was needed to provide the fuel for just one small domestic facility. Based on floor area comparisons alone, that could mean that Caerleon’s legionary baths needed over 13,800 acres (5,600 ha) of woodland to keep them running, unless coal was used instead – which in that case was a real possibility, because there were plentiful sources in the area. Either way, a legionary fortress must have depended on vast supplies of local fuel. However, estimates are based on so many imponderables and unknowns that it is impossible to do more than conclude that the requirements must have been enormous and time-consuming, and probably also had a serious impact on the local environment. This may explain why Caerleon’s baths had fallen into disuse by c. 230, long before the rest of the fortress.
When forts or frontiers were consolidated in stone, the Roman army became involved in quarrying on a similarly grand scale to the gathering of timber. Quarrying not only produced stone for building but also limestone which could be burned to create concrete and mortar; both were used in vast quantities in Roman stone construction, especially in the major buildings of a permanent fortress. Legio I Minervia had a lime-kiln depot at Oversheim, about 18.5 miles (30 km) from the fortress at Bonn. Caerleon’s fortress baths were built using lime obtained by using furnaces fuelled by local coal to burn limestone quarried in the area.
Some of the best-attested quarries are in the vicinity of Hadrian’s Wall. They include the so-called ‘Written Rock of Gelt’, where a number of soldiers took time out to inscribe their names on the quarry face, probably as a quality control measure. One announces:
A detachment of Legio II Augusta. The working face of Apr[ilis?] under the charge of the optio Agricola.
This, and perhaps some of the other inscriptions, then belong to a rebuilding of the wall under Septimius Severus, by which time it was almost eighty years old. One of the reasons was that the Wall had not initially been well built. Although it was dressed with facing stones, the core was made of rubble and mortar. As a result of water ingress and frost, both common problems in the area, some of the facing stones had fallen off and the core had started breaking up. The survival of some of the quarry faces and cuttings made by the frontier garrisons still show how laborious and intensive the building and repair work was, as well as the visible impact on the landscape. In one of the upland sections of the wall at a place now known as Limestone Corner, the rock proved too much even for the normally indefatigable Roman army. They used water and wedges to split apart vast chunks of rock and then lifted some of the blocks out. Others proved more resistant and the work was abandoned. Today some of the blocks still lie in what was supposed to be the wall’s forward ditch, and the wedge holes can be seen.
The Hadrian’s Wall quarries were exploited for military installations. Apart from settlements outside the Wall forts, there were few civilian contexts in the area in which masonry was needed. In more heavily settled regions, it is not usually possible to know whether soldiers working quarries were doing so to fulfil the army’s own infrastructure needs or to meet the demands of cities or civil engineering projects (either of which soldiers could have been working on). The soldiers of Legio IIII Scythica, quarrying at Arulis near Belkis on the Euphrates, usefully recorded their presence for us not only by inscribing their names but also making dedications to Jupiter Optimus Maximus and Silvanus, for whom some created carved niches. One soldier carved ‘Aurelius Carus to Silvanus’. Two standard-bearers of Legio IIII, Julius Aretinus and Julius Severus, and a trumpeter called Rabilius Beliabus, banded together to make a dedication to Jupiter Optimus Maximus Silvanus the Preserver. In Egypt an inscription recorded ‘Annius Rufus, centurion of Legio XV Apollinaris, commander of the marble works at Mons Claudianus under Trajan, the Best Emperor’, referring to a state-controlled quarry that supplied marble and granite for imperial projects. Auxiliaries also found themselves assigned to the quarries in Egypt. Ammonios, a member of Cohors II Thracum, had worked in the quarries and died in service around 143.
The manufacture of ceramic products was almost invariably carried out on-site, or within a few miles at a specialized military works depot. Legio X Fretensis had such a depot dedicated to the production of tiles and pottery at Bin Ya’nei (Jerusalem). Far too fragile and cumbersome to be moved in quantity any distance, tiles were needed in huge numbers to roof timber and masonry buildings in fortresses and forts, and for heating systems. It was also illegal to carry a weight in excess of the equivalent of about fifty roof tiles in a wagon. The resources needed (clay, temper, water and fuel) were generally available in most locations. Legio XX’s manufacturing depot at Holt, about 7.5 miles (12 km) from the fortress at Chester, included kilns, workshops, baths and barracks.
Since tiles survive well, even if broken, they are particularly good evidence for how the Roman army made sure its possessions were clearly labelled. Wooden dies inscribed with the abbreviated name of the legion or unit were made and stamped into many of the tiles found at the sites of Roman military bases across the Empire; for example ‘LEG I ITAL’ for Legio I Italica, based at Novae in Moesia Inferior by the Danube. Such stamps are anonymous and merely name the unit. This was not enough for ‘Julius Aventinus, a soldier in Cohors I Sunicorum’, an auxiliary unit known to have been in Britain between 122 and 198–209. Aventinus wrote his name elegantly into a wet tile that had not yet dried and been fired above the stamp LEGXXVV, for Legio XX Valeria Victrix. The tile was found at the legion’s depot at Holt. It would seem that at least part of the auxiliary cohort had been detailed either to work at the depot for the legion or to collect a consignment of tiles for a military building somewhere in the region.
HORSES AND OTHER ANIMALS
Each legion had 120 cavalry, according to Josephus, writing about the Jewish War in 67. Whether this number was invariably the case is unknown because this is the only reference we have to a legion’s cavalry contingent, the equites legionis, in the first to third centuries. Not enough is known about legionary fortress plans to conclude whether provision was always made for this many mounted troops. Auxiliary infantry cohorts with a mounted component (a cohors equitata) had either 128 or 256 cavalry, depending on whether the unit was quingenaria or milliaria in size. There were also the auxiliary cavalry regiments (alae) with 512 or 768 troopers. The result was that as much as one third or more of the whole auxiliary force was mounted, which in could have meant 75,000 or more in Hadrian’s reign, let alone horses for the servants of the individual troopers, pack animals, and making good losses from war, disease and accidents. Another estimate suggests around 110,000 horses and 60,000 mules were needed for the whole army including the fleets. Accommodation in cavalry forts included the ‘stable-barracks’, where men and horses shared the same building. Horses and other animals also had to be constantly replaced, adding to the logistical complications and manpower needed to manage them.
Obviously therefore, horses were a very important part of the Roman army and were needed in huge quantities. When, during his war against Mithridates, Sulla laid siege in 87 BC to Mithridates’ puppet ruler Aristion in Athens and to the port of Piraeus, he needed 10,000 pairs of mules to help operate his siege engines; all the animals obviously had to be fed and watered. The figure is obviously rounded but gives an indication of the scale.
The mounted soldiers who fought with these horses and took care of them had to be highly trained, skilled and experienced. Not surprisingly, such careers tended to involve specialization. Marcus Ulpius Crescentinus, born in the frontier province of Pannonia Inferior, served for 26 years in the Ala Brittonum, then the Ala Praetoria, and rose to serve in the emperor’s equites singulares Augusti before his death at Rome. Gaius Cominius Commianus must have been especially talented. He was recruited at the age of sixteen as a trooper in the Ala Brittonum but died aged only twenty at Budapest (Aquincum) in Pannonia Inferior.
The value of an exceptional horse to the army, and the prestige of riding it, was recorded in a story attributed to the reign of Aurelian. During his rule, it was said, a horse had been captured from the Alani tribe or some other enemy which could run 100 miles a day for as many as ten consecutive days. The animal was not especially large or handsome, but the soldiers assumed that Probus, then serving as Aurelian’s general, would help himself to it. Probus allegedly dismissed such a notion on the basis that a horse which could travel so far was better suited to someone interested in retreat. He ordered lots to be drawn so that the horse could be allocated to one of his men. By some strange coincidence there were four other soldiers called Probus in the army, and although the general’s name had not been thrown into the urn it was the name Probus that kept being drawn out. The soldiers insisted that he take the horse. The story is an intriguing one but unlikely to be true, at least for the most part. The biography of Probus was not written down until well into the fourth century and belongs to the unreliable Historia Augusta series.
Horses were the most prestigious and the most militarily essential, but far from the only animals to be found on military sites. On the evidence of bone remains, cattle dominated by as much as two-thirds the total number of animals at a fort or fortress, followed by pigs, with sheep or goats the least common. These animals must on the whole have been kept in the vicinity and managed for slaughter and consumption. There were other bones from animals like deer, hare and wild boar, which were hunted for sport and food.
WATER, FOOD AND SUPPLIES
The most essential resource of all was water. Building a fort next to a river might seem to solve the problem of maintaining a convenient water supply. In fact the colossal effort involved in moving quantities of water uphill made it a hopelessly unrealistic solution beyond the provision of small amounts for drinking. Housesteads fort on Hadrian’s Wall relied in part on the local heavy rainfall and a system of tanks that caught the run-off, channelled a constant flow through the fort latrines and disgorged the waste into the vicus outside. Aqueducts were the only reliable means of supplying water, which involved locating a source of water at a greater height and bringing it into the fort or vicus through a combination of raised channels, open leats and buried pipes. Where aqueducts could not be built, or would take too much time, the only alternative was to rely on wells which had to be dug throughout the fort and beyond, such as at the Saalburg fort in Germany.
A cavalry regiment’s requirements were even greater than those of an infantry cohort. An aqueduct was built for (and probably by) Ala II Asturum at Chesters on Hadrian’s Wall between 180 and 184. Since the fort had been commissioned almost sixty years previously, the works must have supplemented existing arrangements or replaced an older system. The water supplied the fort, its vicus settlement, and the substantial military baths and accompanying latrines, located down the slope from the fort towards the river Tyne into which all the waste was channelled. In 216 at Chester-le-Street an unknown cavalry regiment built an aqueduct to supply a bath-house built at the same time, while at South Shields an aqueduct was built for Cohors V Gallorum in 222. Military expertise in this area meant the army was also used to construct aqueducts that served civilian communities, for example in Judaea.
After water came food, but there was a tradition of admiring commanders who encouraged reliance on basic meals. It was all part of the Roman tradition of venerating tough, self-disciplined men of the old school. When travelling round the Empire, Hadrian followed the example of Scipio Aemilianus and restricted himself to ‘camp food’, made up of bacon, cheese and vinegar. Onasander, in his manual of advice for a commander, said it was good practice for a general to live off the enemy’s land to avoid causing damage to his friends and allies. In peacetime food was a major consideration. In war food could occasion a crisis. In 216 BC the Roman garrison at Casilinum (near Capua) in Campania, Italy, was under siege by Hannibal. The Roman troops’ position became desperate as starvation set in. They started by using hot water to soften the leather on their shields so they could eat it. They also consumed rats or any other animals they came across, as well as digging out any plants they could find. The Carthaginians ploughed up the grassy soil round the town to destroy any plants. The Romans responded by sowing turnips, the idea being to show the enemy that they were confident of surviving the siege indefinitely. This enraged Hannibal who thought he was now going to have to wait while the turnips grew. Eventually Hannibal, a man who normally never agreed to terms, had to accept the soldiers offering a ransom for their freedom. More than half the garrison survived. A story emerged recounting how one of the garrison found a rat (or a mouse) and sold it to another man for 200 denarii, only to die of starvation himself while the other man lived.
The Second Punic War provided the Romans with the opportunity to learn the importance of integrating supply chains into a campaign. In 212 BC Hannibal, who was then ravaging Italy, enticed Capua into withdrawing from its alliance with Rome. The city was promptly besieged by a Roman army supported by a grain depot at Casilinum to the north, a fortified river route to the west, and the newly fortified port at Puteoli. In 205 BC, when Scipio put together an army and fleet to sail from Sicily to North Africa to defeat Carthage, the logistics were placed under the charge of a praetor called Marcus Pomponius. ‘Food for 45 days, of which enough for 15 days was cooked, was put on board.’ A remarkable 45 days’ worth of water for the men and the cattle was also loaded onto the ships. Livy was unable to find out for certain how many men were in that army, discovering estimates that ranged from 10,000 infantry and 200 cavalry to 35,000 in total. If we take the lowest estimate, then based on the monthly corn allowance of 64 lb (29 kg; see below), for 45 days each man would have needed around 97 lb (44 kg) of corn. That equates to 441 tons (448 metric tonnes) of corn alone for an army of 10,200.
Of course, one solution was to make sure the army lived off the land as much as possible as Onasander recommended. The notoriously parsimonious and ruthless Cato the Elder led a campaign into the Iberian Peninsula in 195 BC. Realizing it was the time of year when harvested grain was on local farmers’ threshing floors, he told the contractors who would normally have sourced and bought grain on the wider market to go home. ‘This war will support itself,’ Cato said. His decision next to ‘burn and lay waste’ the enemy’s fields might have been a rash one, but the gamble paid off. Cato had spotted an opportunity, but it was not one that could be relied on. In 171 BC, during the Third Macedonian War, fighting seems to have been suspended in the late summer so that the armies could gather corn. Perseus, the Macedonian king, had his men threshing in the fields, while the Romans threshed in their camp.
Keeping any army properly supplied and fed also relied on order. In 110 BC, during the Jugurthine War in Africa, the lazy and ill-disciplined soldiers of the army commanded by Postumius Albinus took to selling their grain rations and bought bread on a daily basis rather than make it themselves. In between times they and the motley crew of camp followers they had accumulated spent their time robbing local people, and helping themselves to cattle and slaves. These they sold to the traders who tagged along in their wake in exchange for luxuries like imported wine. The new general, Caecilius Metellus, had to sharpen up discipline quickly and force the soldiers to live off official supplies.