- Unlike the indigenous Iron Age societies which they dominated and interacted with, the Romans operated an economy which functioned through commodity exchange. Goods and services were ascribed a value, with a monetary system used to create transactions which involved no social obligation between either party, with all such obligations cancelled at the point of transaction.
- The mechanism used to facilitate this commodity exchange was coinage, and it was with the Romans that the first known use of coinage is attested within South West Scotland. The Roman monetary system involved the use of a hierarchy of coins, which varied in composition and value. They ranged from the high-value gold aureus, through the silver denarius and the copper alloy sestersius, right to the Roman equivalent of small change, the small copper alloy as. The Roman monetary system was established during the Republican era, circa 211 BC, and it remained consistent throughout the duration of the empire. Coins were minted centrally at a few locations. Rome was the most important centre of production, but coins were also minted in Gaul. They would then be transported in bulk across the Empire, where they were used to pay soldiers’ wages and to procure the goods and services needed to enable the Roman military to function effectively.
- Coins could be used as a vehicle for propaganda. They were circulated widely, and they were personal items which were in close contact with individuals who were active participants in the day-to-day running of the Roman world. One face, the obverse, always features the bust of the Emperor, or occasionally a close family member, as a means of legitimising family relations, lineage and succession. They also feature a legend which states the name of the emperor and his various titles. These precise details allow the minting of the coin to be dated precisely through comparison with the historical records, and as a result, they are very useful to archaeologists. No coin can be deposited before it was minted, which means it must have been lost or discarded after this date. The degree of wear is also an important way of evaluating how long a coin has been in circulation. Usually, coin finds are used as dating evidence in conjunction with other forms of material culture, such as pottery or metalwork types, as well as literary evidence.
- The presence of a coin struck in AD 19 at Birrens, for example, suggested that this site predated the Antonine date ascribed to the fort during the late 19th century, and hinted at an earlier Agricolan origin for the site. Later excavations carried out there confirmed that, as well as the two phases of stone buildings attributed to the Antonine campaigns, there was an earlier, Flavian phase of timber buildings constructed towards the end of the 1st century AD.
- The high-value Aureus occurs in very limited numbers within the region. An aureus of Vespasian found at Birrens probably originated in the Antonine period (Robertson 1982). Silver coins (denarii) are not common, but they become more numerous after AD 84, when Domitian increased soldiers’ pay.
- The imagery on the reverse side of the coin helped to contribute to its importance as a propaganda tool. Britannia featured regularly on coinage, pictured in a positive light, but asses of AD 154-5 portrayed a more negative image, in a special issue minted to celebrate victory in the Antonine campaigns. Here Britannia was shown subjugated in a pose that appears ‘crouched’ and ‘mournful’ (Robertson 1982, 423). Early Antonine coins, including denarii and asses, have been recovered from Birrens, minted AD 139 to AD 141, while 2nd century AD coins minted during the reign of Marcus Aurelius have been found at Prestwick, and Auldgirth, the latter located very close to the Barburgh Mill fortlet.
- It is likely that higher-ranking officers and officials understood the importance of gift exchange and the web of social debt and obligation that could accrue in such a system. They may have used gifts to obtain loyalty and ensure compliance amongst local communities and their leaders in particular. Roman material culture, which may have been deemed exotic by the locals, could have been used in this way, with small quantities of Roman glass and Samian ware pottery turning up relatively frequently on high-status indigenous sites across the region. One particularly striking example is the hoard of iron objects from Carlingwark Loch, Kirkcudbright, which contains a mixture of Roman and indigenous metalwork. Originally, it was thought to represent an offering made by an individual or group allied to the Roman military, members, perhaps, of an auxiliary cohort with a ‘Celtic’ ethnicity. It is now considered more likely that the material represents locally acquired Roman material, which was then placed in a watery context as an offering by members of the indigenous community.
- One piece of evidence suggests that by the 2nd century AD, local communities were sufficiently well-versed in the concept of commodity exchange and monetisation to be able to manipulate it for their own ends. This is demonstrated by the finding of a die for a counterfeit coin, recovered from beyond the densest area of Roman influence on an indigenous Iron Age site at Brighouse Bay, Galloway. The two halves of the die were from mismatched coins. The products from this mould could have been slipped into general circulation in areas less open to scrutiny by Roman officials. Alternatively, this could mark a genuine attempt on the part of the local community to create their own version of a coinage and a monetary-based system, based on what they had learned and could acquire from Roman interaction.
- Manufacturing and production across the Roman Empire was characterised by industrial-scale mass production, with much of the manual labour undertaken by enslaved people. Many of these slaves were captured by the Roman war machine and sent back to the empire where they might be used in the extractive or manufacturing industries. Many of the objects used by the Roman military would have been produced centrally and supplied to the army in their finished form.
- The Roman Empire operated as a consumer society, where fads and fashions played an important role in emphasising a person’s wealth and status. One important area where an individual or family’s status could be demonstrated was through tableware. A decorative style of pottery from Central Gaul, known as Samian Ware, came in a wide range of styles with complex relief moulded decorations, all produced in a glossy red-brown finish. Samian Ware was manufactured in Trier, in Gaul, and according to Eric Birley, it was so rare in Scotland that the small quantities found at forts like Birrens may have come from the baggage of an individual soldier or civilian. It is unlikely to have been brought on-site as a bulk purchase. Other types of ceramic wares, including greywares and black-burnished wares, are also found, and again they would have been acquired outside the region. Examples of black-burnished wares recovered from Carzield and Drumlanrig would have been manufactured by potters working in southern Britain, in particular Devon and Cornwall. Pottery technologies at this time were sufficiently advanced across the empire to allow the creation of a consistent product, wheel- or mould-thrown and fired to create a uniform colour of fabric, using clays which could be fired consistently in either an oxidised or reduced environment to create a red- or black/grey bodied vessel which might be embellished with a coloured coat of slip to create a distinctive finish.
- The aspirations of all levels of society meant that there were opportunities for manufacturers to employ clever ways of bringing goods which had the appearance of luxury to its poorer members. The wealthiest members of the Roman elite had access to works of art and personal items which were crafted by talented artists, though in many cases those who actually carried out much of the work would have been enslaved people. Glass vessels might be acquired by wealthy military personnel – a piece of vessel glass was recovered, for example, from Drumlanrig – and both Roman men and women might wear jewellery and decorative items. The richest of these were wrought from noble metals like gold and silver and inset with gemstones. For poorer members of society, alternatives could however be acquired more cheaply, dress items of copper alloy, perhaps gilded. Some decorative copper alloy brooches of various designs have been recovered from the region, and the way in which different materials might be utilised by different levels of society is illustrated well by a selection of intaglios, coloured insets featuring carved figures which would have been placed as bezels in finger rings. One example from Carzield fort represents a carved gemstone, a carnelian, and it would have been an expensive item, perhaps worn by an officer like a centurion. Another, from Birrens, was a much cheaper alternative worked from paste glass and probably cast in a mould. Vessel glass would also have been a popular luxury item, but its fragility would have meant that transportation would have been difficult, and it is only rarely found in the military sites of frontier zones. A fragment has, however, been recovered from Drumlanrig.
- As well as an expertise in casting bronze, a copper-tin alloy, the Roman metalworker could create an alloy of silver and gold – electrum – and also, brass, which alloys copper and zinc through the cementation process. Iron would still have comprised wrought iron, as the furnace technologies did not yet exist to allow the production of cast iron.
- The army would have required copious quantities of metalwork. Soldiers would have been equipped with armour and weapons, made from iron, buckles and decorative fittings composed of copper alloy, with a standard and achievements made from gilded copper alloy. Draught animals and cavalry mounts needed iron or copper alloy equipment which included bits and harness fittings, shoes for oxen and hippo sandals, tied into place around the pastern, for horses. Structural metalwork, in particular nails, would be needed for the construction of buildings. And of course, tools would be needed for construction projects like digging defences or erecting buildings of either timber or stone. Equipment and raw materials could be acquired centrally and transported in bulk, but it was vital for the smooth running of the garrison that repairs and replacement items could produced quickly.
- Fabricae and workshops were an important feature of all Roman forts. Iron workers and armourers would have been attached to each legion and probably to the auxiliary units, too. Primary evidence of hearth structures that can be directly linked with metalworking can be difficult to find in archaeological contexts, and while no direct evidence of such a structure has been found at Birrens, excavations by Anne Robertson revealed a square building from the Antonine I phase, which revealed sufficient evidence to strongly suggest that it had once fulfilled such a role. A heavily vitrified crucible fragment was found within it, suggesting that the casting of copper alloy took place there, and a large number of metal items were recorded in its vicinity, too, along with lead spill and iron slag (Stetkiewicz 2010, 20). It is also possible that some heavy ceramic items like hypocaust tiles and roof tiles would have been produced on site, although moving substantial quantities of suitable raw clay might have been impractical in those areas where suitable clay sources were not available locally.