Frontiers, borders and, most recently, ‘borderscapes’ have long attracted the attention of Romanists. Benefiting from such landmark publications as Fergus Millar's Roman Near East (1993) and Benjamin Isaac's Limits of Empire (1990), the eastern provinces have been a particular focus. Geographical coverage is, however, incomplete and the area of North Mesopotamia poorly served. Rocco Palermo's On the Edge of Empires rectifies this by offering an up-to-date archaeological synthesis of the region — approximately between the upper courses of the Euphrates and Tigris rivers — from the time of Trajan's invasion in a.d. 114 to Jovian's cession of the territory in a.d. 363. Covering some 250 years, P.'s explicit aim is to open North Mesopotamia to a broader audience, and it is from this perspective that the volume is reviewed.

It commences with a preface that summarises previous work and outlines the book's structure. Throughout, P. indicates the theoretical basis which, with reference to cultural hybridisation, local groups and the importance of smaller settlements within the rural landscape, sets North Mesopotamia up as a permeable borderland. Thus, the volume is positioned securely within the contemporary genre of post-Romanisation frontier studies. Ten chapters follow, approximately divided between context (chs 1–3), evidence (chs 4–7) and discussion (chs 8–10).

The contextual segment begins by reinforcing the book's theoretical framework and evaluating what is meant by the terms ‘empire’ and ‘hegemony’. This is vital in setting up one of the core points: that the existence of local groups in North Mesopotamia, amongst which nomads were paramount, constituted a ‘third agent’ in the process of exchange between Rome and Persia (Parthian-Sasanian). Following this, the geography and climate of the region is discussed (ch. 2) and P. suggests that Rome's frontier organisation was driven less by ‘Grand Strategy’ than by the simple availability of water which dictated the location of settlements. The segment is completed with a historical overview that dextrously combines textual, archaeological and (limited) epigraphic evidence to provide a satisfying synthesis (ch. 3).

Chs 4–7 constitute a gazetteer of known archaeological sites spanning major and minor settlements, surveys and a detailed excursus on Tell Barri. Discussion focuses on how the evidence reflects periods of Roman, Parthian and Sasanian control, and particular attention is given to route networks. Undoubtedly useful as an anglophone synthesis, the efficacy of P's discussion is nevertheless attenuated by the absence of archaeological plans and the parsimonious illustration of small finds, namely pottery and coins. This is significant as much of the discussion focuses on architecture and, with only a selection of undersized satellite images to serve as guides, full comprehension is difficult. Particularly frustrating is the description of the city of Hatra which, with architecturally diverse temples dedicated to local cults, and an intriguing statue indicating synchronicity between the Sun-God Shamash and Herakles, is clearly one of the most important sites in the volume (ch. 4). Unfortunately, both discussion and illustration are limited. Similar difficulties are encountered in ch. 6 where P. offers some statistical analysis of pottery from Tell Barri. This includes three bar charts that, to be fully intelligible, required printing in colour: even the keenest-eyed reader will struggle to differentiate between the nine different shades of grey exhibited by fig. 6.8. Without their accompanying plans, sections and pottery illustrations, ultimately, these charts raise more questions than answers. Better illustrated is the discussion of a military camp at Ain Sinu that may have been used to recruit and house Arab auxiliaries under Roman rule (ch. 5).

The final three chapters focus on mobility (ch. 8), nomads and Arabs (ch. 9) and the impact of Rome (ch. 10). Ch. 8 considers six routes through Mesopotamia that are known from the Peutinger Map and attempts to reconcile them with archaeological evidence from surveys and satellite imagery. The sites of Nisibis and Singara are identified as major nodes, and the general supposition that the availability of water was the dominant factor in determining economic and military routes that, indeed, followed preexisting lines is supported. The chapter on nomads and Arabs — P's ‘third agent’ — draws on the evidence from classical texts and reintroduces the site of Hatra as a key centre for such mobile groups. Set within a thoughtful introduction, this is a significant offering, not just to the understanding of North Mesopotamia, but to wider debates on the function of nomads in the Roman empire. P.'s assertion that they could, to varying degrees, integrate within the Roman, Parthian and Sasanian systems seems wholly realistic and reinforces the book's underlying emphasis on cultural diversity. The final chapter provides an overall impression of Roman rule which appears to have been restricted to the major centres without imposing on the comparatively undisturbed rural populations.

P.'s rejection of Romanisation as an appropriate model for change (or, indeed, lack of it) in North Mesopotamia is harmonious with the evidence presented. However, it should be tempered with the caveat that, as stressed throughout, the archaeological data are limited and cannot yet offer a detailed understanding of Rome's impact. Perhaps the real value of this work is, therefore, in its lucid synthesis of sites and scholarship that renders the region accessible to the non-expert. Given that this was P.'s primary objective, the volume is undoubtedly a success. The shortcomings could be addressed in a second edition with expanded and updated illustrations. This would enhance its utility, particularly for teaching.