The notion of “frontier” remains one of the most debated topics in the study of the physical expansion of the Roman Empire. What did a boundary represent for the Romans? And, more importantly, how many types of “frontier” can be detected within the empire itself? Although precise answers to these and other questions about Roman frontiers continue to elude specialists, scholars have at least begun to clarify some of the problems surrounding Roman frontier studies. Indeed, the extraordinary diversity of frontier studies itself calls for the reappraisal and analysis of local, minute phenomena to address specifically the motivation behind the design of extensive defensive networks. What such inquiries demand then are comparative boundary studies based on robust, regional appraisals so that more comprehensive samples of Roman defensive networks can be compared not only with one another but also with modern, better understood systems, as Lawrence Keppie did in his provocative study of the eighteenth-century American frontier.1
The recent, exhaustive publication of the proceedings of the Limes colloquia includes analysis of areas such as Moesia and the Black Sea, geographical locations heretofore historically and archaeologically neglected by frontier scholars, and implicitly underscores the need for a comparative approach to effectively understand the role of the frontier throughout the Roman empire writ large.2 The scholarly discourse on Roman boundaries will continue to benefit not only from the active debate and refinement of the field itself but also from the new stimuli of increased data produced by more accurate field analysis with an enlarged scope. By virtue of S.T. Parker’s thoughtful analysis, the limes arabicus is no longer an unknown entity, and the study of other areas, such as Cappadocia and Dacia, is expanding rapidly.3 Admittedly, the archaeological shortcomings and disparities — which shift from region to region — remain conspicuous. It is therefore timely not only to challenge regional diversity and chronologies but also to ask whether the African fossatum and the German limes, mutatis mutandis, bear any substantiated resemblance, either theoretically or physically.
D.J. Woolliscroft’s recent Roman Military Signalling situates itself precisely along the above-outlined methodological lines and makes a significant contribution to the shaping of this still new field of research. Woolliscroft focuses his analysis on the Hadrian Wall and the Rhine frontier and dissects several samples of these two defensive systems. Stressing the importance of communication factors as the motivation for the implementation of military installations, he addresses in a new way questions about the nature of limites. Woolliscroft’s strict focus on the intervisibility between signaling beacons, towers, and fortlets, whether archaeologically tangible or hypothetical, generates a rather persuasive reassessment of defensive samples in relation to their surrounding landscape. In the author’s view, communication is thus the mainstay of the configuration of the linear land frontiers he has monitored, and he succeeds in displaying the existence of a unifying principle. Whether this assumption is applicable to other defensive contexts is a vexata quaestio, and a good deal of field research is still needed in order to assess the feasibility of transferring his conclusions elsewhere.
The introduction provides a short synopsis of the book’s goals along with a concise methodological excursus. Woolliscroft describes in depth his analysis, which consisted of repeated experiments of intervisibility under various sorts of weather conditions and especially through low-level aerial photography. (Incidentally, the performance of low-level aerial photography can be criticized. Operating a camera mounted on a 10 ft. pole under often hostile climate conditions is not an easy task, and the unreliability of the method could easily have skewed the accuracy of the intervisibility appraisal. Thus, it seems that the accuracy of Woolliscroft’s analysis could have been vastly improved by a basic GIS-ViewShed analysis, which would have enhanced the model by taking into account the environmental variables that apply to the ancient landscape under study.) The introduction proceeds by explaining the motivation behind his chosen case studies, emphasizing the necessity of applying this type of problem-oriented research to contexts that are familiar both structurally and historically. Woolliscroft further explains that it remains difficult to employ this approach for defensive networks whose study remains underway.
As the book’s title suggests, Woolliscroft focuses on beacons and signaling stations tout court, which are themselves obscure features in the configuration of Roman frontiers. As such, Chapter One broadly considers textual references for signal transmissions in the Graeco-Roman world and provides a series of literary references ranging from Homer to Polybius (conveniently organized under different headings in Appendix 1). Moreover, Chapter One delineates the essential characteristics of beacon communications from antiquity to today, underscoring benefits and drawbacks in operating such media and evaluating their range performance through all sorts of climate.
But military beacons are certainly not a feature exclusive to the Graeco-Roman world. Enlarging the scope of this study to include non-Graeco-Roman, indigenous entities, such as the network of beacons in 6th BC Guadalquivir Valley, described by Rodriguez, et al. in the regional study of the aforementioned basin, might have opened up other suggestive possibilities and applications for his project.4 Of course including a more diverse group of case studies might also have burdened Woolliscroft’s discussion on the tradition of signaling techniques with an unmanageable territorial context: Woolliscroft’s interest is limited to the Roman world. His book explores whether beacons dedicated exclusively to the transmission of messages existed and, if so, the nature of their configuration. Iconographic and literary sources as well as archaeological evidence fail to clarify the nature of these elusive enigmatic systems. Vast traces of burnt material associated with military installations remain the only substantial physical proof of such structures. Their appearance in the archaeological record — whether through excavations on the Eastern or Western frontiers — is scanty at best. Although the accumulation of further data will either deny or reinforce the validity of Woolliscoft’s postulate — the existence of signaling installations commanding the layout of a defensive network — in the meantime one cannot simply disregard the vast array of signaling options with which the Roman frontiers were equipped.
Woolliscroft then turns his discussion in Chapter One to the nature and problems of the different signaling techniques that were most likely to have been employed on Roman borders. The limited literary evidence does point to a battery of techniques ranging from coded signaling to synchronized water-clocks and torch combinations. That said, I believe that these last two techniques motivate further questions regarding the degree of training and literacy required to command military personnel of different ethnicities in the use of these tools. Woolliscroft also perceptively doubts the efficiency of such systems in situations of grave danger. Instead, he suggests that each signaling technique would have found its raison d’être in its proper local context. For example, although water-clocks and pigeons could not have been viable means of communication over Hadrian’s Wall, they certainly would have proven to be effective in other geographical areas. Woolliscroft does a remarkable job of supplementing the rather thin textual sources with plausible physical reconstructions of the mechanical apparati demanded by each technique. For example, he tests frames and dioptra on the ground, monitoring them to assess their advantages and shortcomings. Therein lies one of the most valuable contributions of this book.
Chapter Two engages with the nuts and bolts of field analysis by focusing on the archaeological evidence of Hadrian’s wall and the Stanegate frontier. Although both the chronological problems of the building program and the visibility of sites located on these two defensive systems make the analysis speculative at best, Woolliscroft’s propositions remain convincing. The assumption that apparent inconsistencies and abrupt deviations of the limes cannot hinge on sloppy designs by Roman engineers is what prompts the author to formulate an alternative reading of the defensive system and its landscape. To that end, Woolliscroft’s examination of the controversial Stanegate frontier argues for intervisibility as the main parameter dictating the installation of its forts and towers. In his account, when forts are obscured by the terrain conditions, a tower provides the means by which communication is ensured, thus creating a chain of stations linked together and corroborated by the road which runs parallel to it. The blueprint thus obtained demarcates a functional communication system of forts and signal towers; moreover, its application becomes valid even in more articulated contexts, such as Hadrian’s wall and its peripheral systems (the object of Chapter Three). In spite of the many chronological problems and the lack of consistently transparent evidence, as in the case of the Vindolanda-Barcombe Hill nexus, Woolliscroft’s analysis validates his thesis. Moreover, he vividly describes to the reader the resilience of these systems and their adaptability to swift, sudden changes in the frontier policy while still maintaining their communication capacities, as best seen in the example of the Birdoswald case study. Woolliscroft’s astute analysis motivates further questions regarding communication direction. Were such signals lateral or essentially North-South, and were those two options mutually exclusive?
Chapters Four and Five describe additional frontier samples taken from the Wetterau and the Raetian frontiers, areas already thoroughly studied and examined by generations of scholars. In so doing, the author enacts a geographical shift that effectively diversifies both the territorial contexts examined and the chronological span under study. The pattern of analysis remains consistent, and the results are consonant with the previous appraisal; however, within a context of remarkable terrain asperity like the Raetian sector, inadequate visual documentation fails to confirm the conclusions drawn by the author.
In conclusion, for all of its interest, this book’s lack of a stable historical perspective undermines many of its merits and characterizes it as a strictly “technical” work. No one can argue with the fact that chronology and building programs of the frontiers analyzed are difficult to pinpoint because of both the archaeological limitations and a lack of informative textual sources. Yet such conditions should never impair the historical contextualization of archaeological phenomena and the formulation of more or less plausible hypotheses, which ultimately can open up new avenues for thought and discussion. Despite this criticism, this is a well-produced work of great originality, which constitutes a substantial contribution to the ongoing debate concerning the Roman frontiers.
Notes
1. L. Keppie, “Armies on Frontiers: Myth and Realities”, in V. A. Maxfield and M. J. Dawson (eds.) Roman Frontier Studies. Proceedings of the XV International Congress of Frontier Studies. Oxford: 455-457, 1991.
2. P. Freeman, J. Bennett, Z. T. Fiema, B. Hoffmann (eds.) Limes XVIII. Proceedings of the XVIII International Congress of Roman Frontier Studies. Oxford, 2002.
3. T.B. Mitford, “The Roman Frontier on the Upper Euphrates,” in R. Matthews (ed.) Ancient Anatolia. Oxford: 254-272, 1998; A.S. Stefan, “Les Guerres Daciques de Trajan: les Opérations du front Alpin,” in W. Groenman-van Waateringe, B. L. Beek, W. J. H. Willems and S. L. Wynia (eds.) Roman Frontier Studies. Proceedings of the XVI International Congress of Roman Frontier Studies. Oxford: 517-525, 1997.
4. A. R. Rodriguez, M. M. Rodriguez and M.C. Lopez, “Settlement and Continuity in the Territory of the Guadalquivir Valley (6th Century BC-1st Century AD” in G. Baker and J. Lloyds (eds.) Roman Landscapes. Archaeological Survey in the Mediterranean Region. London : 29-37, 1991.