Used indiscriminately by the antiquaries, the term ‘camp’ had by the 1930s become a specialist British archaeological term for the temporary encampments — as opposed to permanent bases — of the Roman army, defensible enclosures containing tents rather than buildings, sometimes for the overnight protection of an army or unit on campaign, sometimes for longer occupation. The broad classification is into marching, construction, siege and practice camps, to which we might add semi-permanent transit camps placed at vulnerable points on certain routes. Such temporary works leave slight archaeological traces except in unploughed upland areas, but an explosion in numbers of known camps came in the twentieth century with the development of aerial photography: almost 500 are now known in Britain (constituting the vast majority of those known in the Roman Empire) and almost half of these are in Scotland.

Jones's Roman Camps in Scotland complements Roman Camps in England (Welfare and Swan (1995)) and Roman Camps in Wales and the Marches (Davies and Jones (2006)), effectively completing a three volume corpus of known camps in the British Isles. The biggest of the three, the book opens with a series of richly illustrated general chapters on the ancient written evidence, classification, the history of research, the distribution of camps in Britain and the Empire, an exhaustive discussion of the field archaeology and, finally, the historical background. The second half is a magnificent gazetteer of known, probable and possible camps, with full description, bibliographical references, and an elegant plan transcribed onto the OS background for each. Use of common and natural scales makes it easy to study and compare the plans. This immediately becomes the standard and indispensable work for anyone engaged in the study of Roman Scotland and will be of enduring value. The shorter Roman Camps in Britain, in a popular format, broadens the field to include England and Wales, forming a useful and well-referenced handbook to the subject.

Because we have literary narratives of Flavian and Severan campaigns in Scotland, writers have sought for centuries to link the camps there to events described in the literature. This persists to the present day because in Scotland it is possible to recognise series of similarly sized and shaped camps which evidently represent the advance of particular armies at particular times. The problem, at least until recently, has been the near-absence of absolute dating evidence for any of these series. J.'s handling of this issue is balanced and sensible: she accepts the reality of the four main series, discusses the evidence for their relative dates, and cautiously suggests possibilities for historical context rather than arguing firmly for particular attributions. As she reports, there has recently been a major development: radiocarbon dating suggests that the northernmost series of camps, 44 ha in area, which extends from the Mounth to the Moray Firth, is Flavian, although there remains the complication of possible later reoccupation. The series apparently includes the exceptionally large (58 ha) Logie Durno, whose suggestive situation by the mountain Bennachie led St Joseph to identify it as Agricola's camp at Mons Graupius. J. remains cautious on this. It should also be remembered that a ‘Flavian’ date could be post-Agricolan.

Doubt is now cast on the 25-ha series, traditionally viewed as Severan: these now seem more likely to be Hadrianic or Antonine. For the series of great 54-ha camps extending to the Mounth, apparently the latest in relative terms, J. concludes that: ‘the Severan conquest of Scotland does seem the most likely time frame … on present evidence’.

J. recognises other groups of camps, including those thought to be Flavian because of their distinctive ‘Stracathro’ gate-type, but as they do not fall so easily into recognisable lines of march, they have been less prone to having history woven around them. The same, as J. explains, is true of camps in Wales, where marching sequences cannot be identified with confidence.

J. is also sensible and convincing on the question of holding capacity, considering the ancient texts and the calculations made by various writers from Roy onwards and arguing for the lower (and most often accepted) end of the scale of suggestions: 480–690 men per hectare. This discussion is only found in the shorter book; it is an odd omission from the larger, since a consideration of the size of the forces contained is critical to a discussion of likely historical context for the major series of Scottish marching camps. J.'s argument supports the general rule of thumb that, taking into account the areas of the camp housing not troops but administration, animals and supplies, camps accommodated numbers at about twice the density usually found in permanent forts and fortresses (e.g. a legion of 5,600 housed in a 20-ha fortress would occupy a 10-ha camp, giving 560 men per hectare).

Camps have a reputation for being archaeologically unrewarding, but as J. emphasises in both publications, this has been changed by the advent of developer-funded archaeology. In particular, extensive area excavation ahead of the building of housing estates in the interior of Kintore (one of the 44-ha series) has revealed rows of cooking-ovens, and evidence for the wooden utensils the army carried on campaign, while the ovens have yielded the multiple radiocarbon dates which give the camp and its series a firmer historical context. So far no coherent overall plan has emerged, possibly because the camp was used more than once, but Kintore shows the potential for future area-excavations of camps to yield valuable information. We have reached the end of the era when the most that could usefully or practically be done was to section the ditch.

The arrival of LiDAR also means we may soon see a new wave of camp discoveries throughout the British Isles, and this in combination with developer-funded archaeology could conceivably transform the subject within a few decades. J.'s two books give us a marvellous stocktaking of the knowledge gained through the twentieth-century air-photographic revolution, and point the way to exciting developments in the future.