Binchester fort in County Durham lies 22 miles south of Hadrian's Wall. Very little is known of its interior except for some late Roman internal baths attached to fragments of the praetorium. The baths, among the best preserved in Britain, were described in 1891 and were again the focus of excavation in 1976–81 and 1986–91 in connection with the protection and display of the remains. Ferris now presents a final report and summary publication. There were finds of exceptional interest, such as remarkable graffiti on tiles from the baths, including a list of 25 soldiers’ names in fourth-century cursive, rare evidence for ethnic origin and literacy in the late Roman army of North Britain.

The baths are described in detail, though without reference to baths elsewhere in Britain or the Empire. F. accepts the traditional view that they were for the private use of the commander, not considering whether this might have been a late Roman internal baths for the soldiers, as a comparison of the size of the building with other military baths might have suggested. A conservative line is also taken on the well-known tiles in the baths stamped N CON, accepting that they refer to a unit from Chester-le-Street (Concangis), 14 miles away, although there are other possibilities — perhaps a unit named something like numerus Constantinianorum (cf. ND Oc. VII, 149)?

The earliest fort, founded c. a.d. 80, was exceptionally large (roughly 7 ha). Excavation of the earliest levels was limited but found fragments of a high-status building, superseded in the first half of the second century by rubbish-dumping and iron-working. In the mid-second century the fort was reduced in size to its visible 3.6 ha and the first phase of the praetorium built (Phase 6).

The report's showpiece is a structural sequence running into the sub-Roman period, with an impressive suite of over 20 radiocarbon dates that offers the prospect of anchoring such a sequence in some kind of absolute chronology. The later chronology argued for in the report is as follows: the praetorium is rebuilt in stone after a.d. 270 (Phase 7), and again more grandly, c. 335–45 (8A). The internal baths are not added until c. a.d. 350–60 (8B), with modifications (8C) followed by major additions (8D). The baths remain in use to the end of the fourth century, after which there is a phase of rubbish dumping contemporary with craft and animal slaughtering activities in the praetorium rooms. This is overlain by dumped clay and rough paving associated with antler-working. This occupation (Phase 9) is possibly still current when a high-status Anglo-Saxon inhumation is dug through the collapse of the bath building in the mid-sixth century. The general argument is that late Roman Binchester and its large vicus acquired a quasi-urban function as a regional centre. This entails the maintenance of the praetorium in high style to c. a.d. 400 and makes Binchester a place of continued importance in the fifth and sixth centuries.

The report tends to push structural developments as late as possible, when in reality they may have occurred earlier. Phase 7 is dated as a whole from a single radiate coin sealed beneath a wall; many of the other ‘Phase 7’ walls are retained, stone-for-stone, from the preceding Phase 6 plan (cf. figs 17 and 18). The terminus post quem for Phase 8A is a single coin of a.d. 335–45 sealed in the foundations of an opus signinum floor, judged to be primary. Can a single wall or floor, each possibly a modification to an existing structure, really date an entire building phase?

The dating of the addition of the baths to the second half of the fourth century is unconvincing and difficult to parallel. The dating is based on a coin of a.d. 350–60 from a foundation trench of the west praefurnium, but in the larger report (67) an earlier set of walls is described, suggesting that the extant praefurnium was not the original. A wall of Phase 8A (a.d. 335–45, if correctly dated so late) was truncated to make way for the baths, but this need not have been long after the inception of Phase 8A and it seems inherently likely the baths were added in the a.d. 330s or 340s when the coin record indicates extraordinary activity at Binchester. Nor can the ‘8D’ addition to the heated block be much later: misunderstood in the report as an entrance hall and changing room, it is in fact the frigidarium (as two cold plunge baths confirm), without which the baths cannot have functioned.

The rubbish-dumping that signals the disuse of the baths was rich in finds, including the latest types of Roman pottery. But the latest of 141 coins from these deposits were of a.d. 350–60, while the Bayesian modelling of ten radiocarbon dates places the end of this phase in cal a.d. 370–410 and probably cal a.d. 380–400. From the subsequent horizon associated with antler-working, four statistically consistent radiocarbon dates were obtained. Combined in the Bayesian model these indicate that this phase ended by cal a.d. 380–450 and probably by cal a.d. 390–430. The decay of the fabric of the baths immediately follows. F. casts doubt on the modelling but seems to be brushing aside the science because it does not fit the preconceived idea of a long sub-Roman chronology.

The evidence could support other equally interesting models of fourth-century transformation. The coin report points to the a.d. 350s as the decisive time when the arrival of newly minted coins fell to and remained at unusually low levels. Between c. a.d. 360 and c. 400 continued occupation elsewhere must have produced the rubbish dumped around the baths. One possibility is that the military occupation had contracted and that after c. a.d. 360 the baths were abandoned, with the investigated areas lying outside whatever part of this large fort was still in use. Whatever the nature of the final occupation, the scientific dates suggest that it ceased at least a century before the Anglo-Saxon use of the site for burial.

Specialist readers of the big report and the undergraduates and general readers at whom the shorter book is aimed are thus offered an indispensable mine of information, but would do well to consider this evidence for themselves and to engage critically with some of the interpretations placed upon it. Whatever your stance on the ‘late Roman transition’, F. and his collaborators are to be thanked and congratulated for bringing to completion one of the most important excavation projects of recent times in the military North.