Roman towns present enticing targets for geophysical survey. Their gridded streets and masonry buildings respond to a range of survey techniques, and the results are highly visual. Improved rapid survey techniques involving multi-sensor arrays mean that large areas can be covered rapidly. It is also cheap, relative to other forms of archaeological investigation, making it attractive to those working at universities, where research budgets grow ever tighter. Little wonder then that the last two decades have seen an ever-increasing number of surveys on those town sites unencumbered by modern development. In the UK, Wroxeter, Silchester, Caistor-by-Norwich, and Verulamium have all seen large-scale geophysical investigation, while elsewhere in the Roman Empire major surveys have been carried out at Carnuntum (Austria), Ammaia (Portugal), Falerii Novii (Italy), and many other sites.Footnote ¹

Now we can add Aldborough (Isurium Brigantum) in North Yorkshire, UK, to this number. The Aldborough project began in 2008 and encompassed large-scale geophysics alongside field survey and some limited excavation. The first result is this attractive volume by Rose Ferraby and Martin Millett. Its 187 pages are divided into four chapters plus lengthy appendices cataloguing all the earlier interventions at the site.

The volume opens with a brief discussion of the historical context of the site. Isurium Brigantum was the civitas capital of the Brigantes, chiefly famous as the people of Cartimandua, who favored and was supported by Rome in the turbulent decades following the conquest of Britain, before her eventual overthrow in 69 CE. The region was eventually annexed by Rome in 71 CE. The focal point of Cartimandua's territory was apparently the well-explored site of Stanwick, which received high-status goods from the Roman world from the end of the 1st c. BCE. Stanwick, however, was passed over as the site of the capital of the civitas of the Brigantes in favor of Aldborough 50 km to the south. This has in the past led to the assumption of a military origin for Aldborough, an interpretation that persisted throughout the 20th c. The name Isurium is noted by Ptolemy and in the Antonine Itinerary, but also appears in two of the Vindolanda tablets, both referring to it as a settlement along Dere Street involved in the movement of goods to the frontier.

The introduction is followed by detailed discussion of earlier work at the site (Chapter 2). Antiquarian interest is known from the 16th c. onwards, by which time Aldborough had already been identified as the site of Isurium. In the late 17th and 18th c., letters of the Reverend Edward Morris recorded multiple discoveries including coins, intaglios, mosaics, and other structural evidence in fields around the town. Some of these finds are marked on early maps of the village by Smithson, created as part of a survey commissioned by the Duke of Newcastle, with the first proper attempt at a plan of the walled Roman town drawn by Francis Drake in 1736.

Successive discoveries through the 18th c. included, notably, the excavation of part of the forum in an area adjacent to the church in 1770, recorded in two different plans. The 19th c. saw significant exploration of the town under the patronage of Andrew Lawson, the owner of Aldborough Manor. Lawson's excavations led to the creation of a museum and the publication of Henry Ecroyd Smith's Reliquiae Isurianae in 1852, which compiled, with considerable accuracy, the evidence recovered to that point. Intermittent later 19th- and 20th-c. excavation was of varying quality and seldom published to any extent but was synthesized by John Wacher and also Colin Dobinson, who produced a revised plan of the town and initiated further fieldwork, the results of which are drawn on by Ferraby and Millett in their interpretations. More than 30 other interventions have taken place from the 1990s onwards as a result of building work. This chapter is supported by a large gazetteer in an appendix, which lists (with references) all known previous archaeological interventions at the site in chronological order. This gazetteer will be an invaluable reference work in its own right and will form a starting point for all future investigation of the site.

The geophysical surveys, which are the subject of Chapter 3, form the core of the book. The results were gathered using fluxgate gradiometers with additional use of ground-penetrating radar (GPR). The surveys covered an area of around 100 ha and spanned both the intra- and extra-mural areas of the Roman town, although the presence of the modern village meant that survey of the central area was only partial. The different datasets were combined within the project GIS with interpretations produced in Adobe Illustrator.

The success of publication of geophysical survey hinges on the quality of the graphic presentation. Here the survey zone is divided into 13 areas, which are discussed in turn, with the authors in the main following the well-established path of presenting plots of the gradiometer data alongside the interpretation. Plots of the GPR data are not reproduced alongside the gradiometer plots and the reader is thus unable to compare the GPR interpretation with the original data. This is occasionally unsatisfactory because the limits of the GPR survey are not made clear on the plots and the reader is thus unable to easily see variations between the results of the gradiometer and GPR surveys in the areas where they apparently overlap (e.g., in Area 4).

GPR and gradiometer interpretations are presented separately. Ferraby's graphic interpretations are a model of clarity, with different types of gradiometer and GPR anomalies differentiated through color codes. The interpretation plans include previous findspots, allowing relatively easy cross-referencing with the gazetteer described above. The result is attractive and easily navigated, although this reader missed having an image of the survey dataset in its entirety. Presumably this was left out because the scale would mean that any detail would be so illegible as to be meaningless. Orientation comes via a schematic plan of the different survey areas in relation to the modern village.

What then does the survey tell us about Isurium Brigantum? Notwithstanding the complexities of survey in an area that has much more modern occupation than the greenfield sites noted above, the results reveal a significant density of archaeological features. Interpretation is made more complex by medieval ridge and furrow ploughing and traces of medieval tofts, alongside the disturbance of recent construction and buried services.

The town was enclosed by a wall, the line of which is still apparent in places, and this defines the survey areas to some extent, with the intra-mural zone surveyed as Areas 1–4. This division is partly because the modern settlement is focused within the walled area, rendering large areas inaccessible to magnetometry survey. The northern part of the walled zone (Areas 1 and 2), however, includes large areas of open fields and landscaped gardens (the latter less susceptible to investigation through magnetometry). Here the northern half of the orthogonal street grid (including the principal east–west street) could be clearly identified, along with a range of substantial masonry structures including possible courtyard buildings, baths, strip-buildings, and what the authors suggest is a twin-celled temple complex, although other explanations (e.g., a bath complex) seem equally likely. Also of interest is what appears to be at least one substantial warehouse measuring some 60 x 28 m in the northwest corner of the town, which is intriguing in relation to Aldborough's role in military supply.

The central part of the town, which includes the forum, is one of the most densely occupied parts of the present settlement and as a result, only small areas could be surveyed (Area 3). GPR identified the likely southern and western ranges of the forum, while the location of the northern range (first uncovered in 1770) was confirmed through limited excavation. Intriguingly, St Andrew's church occupies the central part of the forum. Although the present building dates to the 14th c., it is tempting to envisage an earlier origin, the forum location being reminiscent of that of St Paul in the Bail in Lincoln (still the most convincing candidate for a Late Roman church in Britain). Much of the understanding of this area derives from antiquarian excavations and chance discoveries detailed in the gazetteer. It is clear that there were substantial town houses with impressive mosaics of probable 4th-c. date inside the west gate, and there is a sense from the antiquarian finds that these continued along the main east–west street.

The southern part of the town was apparently laid out over three substantial terraces. The southwest quadrant (Area 4) is now mainly within the grounds of Aldborough Manor and includes the parts of the site visible to tourists today. The area has been the subject of considerable landscaping and here the benefits of GPR are most apparent, revealing substantial buildings that were all but invisible in the gradiometer survey (e.g., a large masonry building now beneath an outdoor auditorium). Earlier excavations on the grounds of the Manor revealed a number of large structures with mosaics including what appears to be a large apsidal triclinium, and it seems that the area contained several major townhouses, with the three terraces noted above allowing elevated views over the landscape to the south.

The southeast part of the walled zone (Area 5) is largely occupied by modern housing and so afforded little opportunity for geophysical survey, although the Roman terraces and streets are preserved to some extent in the modern topography and road system. Watching briefs during the replacement of gas mains are noted on the plans, although the gazetteer contains no discussion of what was found beyond “Roman wall deposits.” However, other antiquarian finds of walls and mosaics suggest further townhouses in this area.

The remainder of the survey focused on the extra-mural area and employed gradiometer survey exclusively. The walls are surrounded by a complex multi-vallate system of four concentric ditches (revealed on the southeast and northeast corners, in Areas 6 and 9 respectively) first excavated by Margaret Jones in 1964. The defensive circuit seems to have been augmented with two irregular ditched annexes on the north and east sides of the town, which constitute some of the more novel results of the survey. They provide additional defended areas in front of the north and east gates, and the authors postulate that they had an official function, offering secure storage outside the town for supplies and animals in transit. This is reinforced by the presence of what seems to be a substantial building within the north annex, which can perhaps also be seen in the context of the large intra-mural warehouse noted above. Finds of Late Roman lead seals from Aldborough also clearly attest to state involvement at the town. Also of interest is an enclosure that appears to truncate the banks of the town's boundary ditches on its east side. The authors suggest that this could be Late or post-Roman in date.

On the southeast corner, the survey confirmed the previously rumored presence of an amphitheater just to the exterior of one of the most complex sections of the multi-vallate ditch system, which apparently truncated the north part of the earth seating bank. An oval anomaly indicated the presence of an internal revetment wall around the arena. There is little sign of a major masonry phase.

On the east side, the major road that led southeast towards York could be clearly identified before it merged with the line of the present road, which follows the course of its Roman predecessor (Areas 7 and 8). The road is flanked with a series of enclosures that contain significant anomalies, some identifiable as buildings. These are interpreted as funerary enclosures based on their extra-mural position and the form of the structures. Anomalies apparently indicating burning are associated by the authors with cremations. This seems a reasonable interpretation, although as with John Creighton's identification of cremation pyres on the periphery of Silchester, it is something that could be readily tested through very limited excavation.Footnote ² Certainly the geophysics suggests activity of relatively unified character, involving a series of small plots and anomalies indicative of small structures, although this could perhaps be industrial rather than funerary. We might note that the area to the southwest of the town (Area 13), where cemetery evidence was discovered in the 19th c., produced markedly different geophysical results.

On the north side of the town, the line of Dere Street was traced for some distance as it left the north gate flanked by a series of enclosures that were of markedly different character from those described above (Areas 9 and 10). The enclosures are larger and the evidence for buildings less clearly defined, although the contrasting anomalies flanking the road suggest structures that have been heavily disturbed by agriculture. The authors suggest that these enclosures and structures were agricultural and domestic in nature. The line of Dere Street can clearly be discerned as it turns slightly to a point where it bridged the River Ure.

Activity to the west was less clearly defined, although the line of the Roman road can be inferred from the alignment of further enclosures that presumably flanked it (Area 12). An intriguing, more radial system of trackways and enclosures can be seen to the south of this road. At least one large building of hall-like plan can be seen, apparently situated on top of an enclosure ditch. Much larger and less regular enclosures can also be seen to the southwest of the town (Area 13), along with possibly Roman quarries.

Chapter 4 seeks to interpret the results of the surveys in relation to those of earlier surveys and excavations and to place the town in the broader context of Roman Britain. There remains no evidence for a pre-Roman focus at the site, and the earliest activity perhaps relates to the Roecliffe Roman fort to the west, which probably dates to the reign of Vespasian. Certainly the evidence from the town points to quite intensive activity from the 70s CE. Whether this is military or civilian in nature is hard to tell, although Ferraby and Millett argue tentatively for the latter. There is no clear evidence of a fort, with discoveries of military tile stamps mainly of late or post-Hadrianic date and thus apparently associated with the civic development. It is argued that Aldborough develops due to its riverine connections and comes into its own as a trade and supply base facilitating the Agricolan advance (here we can note the references to Aldborough in the Vindolanda tablets) and associated with burgeoning lead and silver mining in the Pennines. This is certainly reasonable, although we might quibble that the geophysical survey added little to this interpretation.

The survey did add to our knowledge of the street grid, significantly augmenting the previous plan of the site by Colin Dobinson. As is often the case with geophysical surveys, the additions suggest a rather less regular creation than the idealized orthogonal vision of earlier scholars. Ferraby and Millett argue that the grid was laid out in a single act of planning at the same time as the forum, an interpretation which they admit is at odds with the evidence from most towns in Roman Britain, where the development of street grids appears to happen incrementally. I was not wholly convinced by this, but certainly the creation of the three substantial terraces to the south of the forum is indicative of major centralized investment. Ferraby and Millett place the construction of the forum (apparently in masonry from the outset) and hence the street grid in the Hadrianic period, along with the construction of the bridge over the River Ure. A Hadrianic sewer system is also suggested. Refreshingly, they argue against direct imperial involvement associated with Hadrian's visit to Britain in 122 CE, bucking a long-standing tradition in Britain in which Hadrian is credited with any sign of urban development.

Beyond the forum and a possible 2nd-c. bath complex, understanding of the public buildings of the town is limited, although there may be temples of Classical type, while sculptural fragments and limited epigraphy attest to cults of Jupiter, the Matres, and Mercury. Architectural fragments in millstone grit from earlier excavations are, according to Ferraby and Millett, from domestic rather than public buildings.

The town wall is placed by Ferraby and Millett in the second half of the 2nd c., albeit on the basis of limited evidence. They argue that civic status rather than defense was the principal motivation, highlighting the limited view from the town over the approaches from the south and east, rendering the wall fairly ineffective for defense. The rather irregular form of the northeast corner and the slight angle of the north wall remain unexplained. The wall was augmented with external towers and the complex ditch system, of which the latest elements are suggested to be as late as 400 CE. This is an intriguing hypothesis, and the authors go on to suggest that Aldborough remained a key site as late as the 7th c. Although their basis for this argument is necessarily slight, it is a suggestion worthy of further investigation. The ditched annexes to the defensive system are probably of Late Roman date and suggest the site remained important as a supply base through the 4th c. if not beyond.

This volume deftly knits together the evidence to paint a picture of Aldborough as a town that is very specific to its context, tied into the broader currents that shaped Roman Britain. It is clear that its position on Dere Street linked its fortunes to supply of Britain's northern frontier, attested through mention in the Vindolanda tablets in the 1st c. and through official lead seals in the 3rd. The geophysical survey enhances our understanding of the town's apparent role in military supply through its indications of large warehouses and extra-mural enclosures.

As with the other towns investigated through large-scale geophysical surveys mentioned at the start of this review, notwithstanding the scale of the area covered and the visual impact of the survey data, the authors’ interpretation of Aldborough remains heavily informed by the skillful synthesis of piecemeal and often unsatisfactory earlier interventions. The results give a clear overview of the topography of the town, but the reader is sometimes left with a sense of more questions raised than answered.

The geophysics show the extraordinary complexity of the buried archaeology, but the picture that emerges in the synthesis is in some ways quite a traditional one, charting the development of the town and discussing the familiar elements of the urban landscape – walls, streets, public buildings, etc. – and attempting to fit them into a chronological framework within a broader historical narrative of Roman Britain. While this in itself is a valuable exercise, the seductive nature of low-cost mapping of Roman towns should not distract us from seeking to answer more difficult questions regarding the lives of those who lived within their walls. This important book provides an excellent basis for such future endeavors.