Roman Aldborough is the most northerly, as well as one of the smallest, planned towns of Roman Britain, its later Roman town walls enclosing only some 21.6ha. Its Roman name, Isurium Brigantum, indicates that it was the administrative centre for the territory of the Brigantes. As it lies beneath the village of Aldborough, with space at a premium for extensive survey and excavation, it had previously seen very little archaeological investigation—the last major excavation was completed in 1964; field survey of extramural areas was undertaken in the 1980s and the early 1990s—before the projects of 2009–2017 described in this volume. The core of the new work is the publication of geophysical surveys, mainly using fluxgate gradiometry, but also, within the walled area, ground-penetrating radar; the total area surveyed amounting to about 100ha. These surveys were complemented by an analysis of the lidar data to enhance the topographic record of the site and an invaluable Gazetteer of archaeological interventions (Appendix 1). The results are elegantly presented with fine illustrations and represent an important advance in our knowledge of the Roman town and its environs.

The survey within the town walls has provided, for the first time, evidence of a street grid, initially, perhaps, no more than two blocks either side of the insula containing the forum, now buried beneath St Andrew's church, and extending over 17.6ha. The arrangements are particularly clear in the northern half of the town. Outside the town walls, the survey has brought into sharp focus the importance of Dere Street, the road leading north from York to the northern frontier, with evidence that it was built up with strip plots lining the road for some 700m as it headed into the town from the east and then out through the north gate for a similar distance towards the River Ure. In contrast, the roads leading out to the west and south show only light occupation, with the ground between them divided into irregularly shaped and sized enclosures by trackways heading out into the deep countryside.

What of chronology? There is not much to go on yet, but a small excavation by the authors, yet to be published, confirmed the position of what must be the forum at the centre of the town and provided evidence for “a sound terminus post quem of c. AD 120” (p. 104). Although its dating is not confirmed, the construction of the forum is seen, quite reasonably, to go hand-in-hand with the laying out of the street grid. Such developments would be consistent with the idea that the civitas Brigantum was established at this time with Isurium its administrative centre, as is implied by the tribal suffix in the name IsuBrigantum recorded in the Antonine Itinerary, which was probably compiled in the early third century. An amphitheatre, not aligned with the grid, is confirmed beyond the town walls, which it pre-dates, on the south-east side, and the town walls themselves have been dated certainly to later than c. AD 170, but quite possibly later than a coin dated AD 238–249.

The emerging picture puts Aldborough on a par with Caerwent, Isca Silurum, where, again the construction of the forum basilica with a terminus post quem of AD 110–120 is linked to the establishment of the civitas (Guest Reference Guestin press). Not only is the later walled area of Caerwent close in size to that of Aldborough, but the location of both towns in close proximity to the legionary fortresses of Caerleon and York suggests that their establishment was governed by the same decision. The proximity to the fortresses suggests a degree of pressure on the part of the military to find accommodation for the generation of soldiers retiring since the last de novo foundations of coloniae in Britain at Gloucester and Lincoln at the end of the first century AD, or to use veterans to manage administrative matters previously handled by the legion, or both. Whether that decision was made by the provincial governor rather than by the Emperor Hadrian, as John Wacher argued (Reference Wacher1995: 378–407) will probably never be known, but Hadrian, with his close interest in the Roman army, would surely have been made aware of concerns about the welfare of retiring veterans when he visited Britain in AD 122. Equally, the decision to use significant legionary manpower and resources to build the new northern frontier may have required fundamental changes in arrangements previously organised at legionary headquarters.

There is much to learn about the roles played by Aldborough and Caerwent: in neither case do we have any idea of the extent of the civitas that they administered and the scale of the burden placed upon them. Neither town appears to have had much impact on their immediate hinterlands in terms of, say, villa development, but the trackways detected leading out of Aldborough suggest some of the population engaged in farming the surrounding landscape. More than relying on agriculture, their locations did at least give each of them a secure economic base. On the road north to and from Catterick and the northern frontier, Aldborough could play a key role in the support of military supply and the movement of personnel on a vibrant strategic route, as the ribbon development along Dere Street implies. Caerwent, closer to Caerleon than Aldborough is to York, and on the main road to and from the legionary fortress, also surely profited from through traffic. These speculations show how much more there is to learn about both of these towns, but Isurium Brigantum provides us with the essential foundation upon which to build future research at Aldborough.