Ghislaine van der Ploeg has tackled a subject that has rarely been the focus of scholarship on the cult of Asclepius: the god’s cult in the Roman world. That scholars have tended to concentrate on Asclepius among the Greeks, especially before the coming of Rome, is certainly understandable, since with few exceptions the most varied and interesting literary and epigraphical texts concerning him are from the Greek East, as is also true of artistic representations. But for those who have known where to look there has always been much of interest in the cult of Asclepius in the Latin West, and van der Ploeg has demonstrated this by focusing on several interrelated issues concerning who was worshiping Asclepius in Roman times and how his cult would spread or, in parts of the Greek world where it was already established, rise in status. Van der Ploeg, whose book is based on her 2015 dissertation at the University of Warwick, did not set out to write a comprehensive study of the cult in the Latin West and post-Hellenistic Greek East: instead, as her title states, the book’s goal is to show the “impact” of the Roman Empire on this Greek cult. Thus the bulk of her study is devoted to the interactions of certain Roman emperors with the cult of Asclepius and his prominent role in the religion of the Roman army, two underappreciated factors in the cult’s popularity and growth in Roman times. Van der Ploeg has achieved her goal successfully, making an important contribution that expands our understanding of the cult, and justifiably shines a spotlight on our sources for Asclepius’s worship in Roman times (specifically, 27 B.C.E.-235 C.E.), though of necessity excluding much evidence that is not directly relevant to her thesis.
Van der Ploeg’s well-illustrated study is divided into five main chapters, sandwiched between short introductory and concluding chapters, with both the Introduction and Chapt. 1 establishing its context and goals. As is most evident in Chapts. 3-5, van der Ploeg’s book is not simply a work of religious history, but rather an examination of several aspects of Roman history – primarily the activities of certain emperors, the Roman army, and provincial life – from a previously overlooked angle. Among van der Ploeg’s chief concerns is the spread of Asclepius’s cult, which by the end of the Hellenistic Period had already expanded throughout the Greek East and found multiple footholds in the western Mediterranean as well, but would be introduced to more lands by the Romans, particularly their army. As she notes, the increased mobility and cross-provincial connectivity that was possible under the Roman Empire were critical factors in this “dissemination.” To van der Ploeg, the ways the cult spread and gained popularity among certain segments of Roman society make it a good case study for the “dynamics of empire,” especially how religious life in the provinces was affected by the Romans. This can be seen not only in the evidence for the army’s role in introducing the cult to new areas, but also in the roles played, respectively, by specific emperors in raising Asclepius’s profile and by the elites of various cities in elevating Asclepius’s local status as part of civic competition with other cities. After describing these and other developments in Asclepius’s cult in Roman times and outlining her theoretical frameworks, van der Ploeg continues to Chapt. 2, entitled “Asclepius before the Roman Imperial Period,” which surveys the cult’s history back to the Archaic Period along with the relevant scholarship, providing important context for the rest of her study but not breaking new ground.
New ground is broken, however, in the next chapter, “Imperial Relations with Asclepius,” which is the best and most extensive study of Roman emperors and this cult, and arguably the book’s foremost contribution. Not all emperors, of course, had a particular attachment to Asclepius, and most cannot be tied to him at all, but Claudius and especially Hadrian and Caracalla are each linked to at least one Asklepieion, and it is these three on whom van der Ploeg focuses, ultimately achieving a case study that illustrates the “top-down” effects emperors could have on any cult. In general, emperors would have an impact at particular sanctuaries – either those they had visited or were patronizing from afar – not in terms of rituals, but rather in the form of concrete changes (e.g., new buildings) and abstract ones (e.g., greater stature). As van der Ploeg shows, in either case the emperor’s actions would create a ripple effect evident in changes at sanctuaries elsewhere in the region, and even in the status of the cities they had honored in this manner relative to those they had not. Given the clear benefits of imperial patronage for a sanctuary and, in turn, how a city fared in the ongoing civic competitions that were a feature of Roman provincial life, local elites and members of the imperial court would use their influence to seek it. Van der Ploeg examines the relations between these three emperors and the cult of Asclepius – most notably at Pergamon, but also Epidauros and Cos – by looking at their own motivations for patronizing the cult, the ways that non-imperial elites would encourage their benefactions, the impact of imperial visits to Asklepieia on the cult, and how such visits and long-distance patronage affected local and provincial political dynamics beyond the temenosboundaries.
Van der Ploeg’s twenty-page section on “The Impact of Courtiers on the Cult of Asclepius” highlights that of one imperial associate in particular: Gaius Stertinius Xenophon, a member of Cos’s elite who had attended upon Claudius as his physician. Using literary, epigraphical and even numismatic sources, she explores how Xenophon helped to obtain imperial benefactions for his patron god’s famous sanctuary back home, and in turn capitalized upon this achievement and his prominence in Rome to boost his status after returning to Cos. Though Xenophon’s professional status and role in benefitting his hometown Asklepieion were different from those of other individuals known to have used their influence on an emperor for the good of Asclepius’s or another god’s cult, he serves as an excellent illustration of how imperial benefactions for a cult site (or cult in general) did not always originate with the emperor himself, but sometimes were the result of lobbying by a well-connected individual – one who may well have stood to benefit both directly and indirectly.
The rest of Chapt. 3 is devoted to a rather lengthy exploration of Asclepius’s cult and “imperial sacred travel,” of necessity focusing on Hadrian, who visited the sanctuary at Epidauros and very likely that of Pergamon around 123-4 C.E., and Caracalla, whose tour of Asia Minor brought him to Pergamon in 213-4 C.E. These two well-traveled emperors had lasting impacts on the major Asklepieia at these cities, especially in terms of Hadrian’s involvement in the remodeling of the Pergamon sanctuary, but also at other cult sites that they never visited. In the case of Caracalla, van der Ploeg shows how he indirectly revitalized the cult of Asclepius in other cities of Asia Minor that established festivals of the god and put him on their coins, taking their cue from his demonstrable interest in the Pergamon Asklepieion – an interest that Pergamon proudly advertised by striking medallions featuring Caracalla and Asclepius. Hadrian, too, van der Ploeg argues, by visiting one or both Asklepieia had an effect on the cult beyond mere benefactions, including having “fostered the development and creation of the god Zeus-Asclepius… a universal deity whose worship would be open for and acceptable to all people in the provinces” (p. 114).
This treatment of Asclepius and Roman emperors is followed by a similarly ground-breaking study of his worship by Roman military personnel, in a chapter entitled “Asclepius and the Army.” Though not perceived as a so-called “military god,” there is widespread evidence for Asclepius’s importance to the Roman army due to the belief in his abilities to both heal and protect, and this led Rome’s legions to introduce the cult to new lands, just as they are known to have done for other gods. Chapt. 4 is thus divided between surveying the evidence for the role Asclepius played in providing “healthcare” for the Roman army – as indicated primarily by dedicatory inscriptions, often from military encampments – and investigating the extent to which the cult’s spread can be attributed to the army. Van der Ploeg’s focus is drawn to the Balkan and Danubian provinces, since a significant legionary presence in these regions led to a large number of official and private dedicatory inscriptions by military personnel, and also because the cult of Asclepius did not reach any of these provinces besides Thrace before the Romans’ conquest and therefore Rome’s influence – including that of its army – is more readily detected. (Also of note, van der Ploeg shows in a discussion of the syncretistic association of Asclepius with certain Balkan “rider gods,” such as Asclepius Zimidrenus, that sometimes Roman military personnel would bring a god back to Rome – an instance of “multi-directional religious mobility.”)
Chapt. 5, “The Cult(s) of Asclepius in Roman North Africa,” is likewise devoted to the Roman army’s worship of Asclepius in the provinces. Building on Nacéra Benseddik’s major 2010 study Esculape et Hygie en Afrique, van der Ploeg argues that the sources reveal a tale of two cults: the Punico-Phoenician god Eshmun, worshiped in Africa Proconsularis and Numidia long before Roman times, had come to be associated with Asclepius in Carthage as far back as the fifth century B.C.E., but during the Imperial Period the traditional Greco-Roman god gained preeminence, apparently spreading from east to west. Van der Ploeg explores the important role of Legio III Augusta in this process, with the god’s great popularity among its personnel being evident at multiple sites, especially the encampment at Lambaesis. Thus in these provinces, too, the Roman Empire, with its army acting as the agent, had an impact on religious life, with greater interconnectivity and mobility facilitating the spread of Asclepius’s cult.
Van der Ploeg’s book is impressive because of the numerous areas of scholarship that she has synthesized, though neither the bibliography nor the references are comprehensive. Perhaps revealing the work’s origin as a dissertation, van der Ploeg typically provides a small number of representative citations – and not always the most important – even for topics with large bibliographies, and while this practice does not adversely affect her analysis, it reduces the work’s usefulness. There are also several points at which van der Ploeg’s arguments are questionable: e.g., her discussion of Asclepius’s syncretism with the Thracian Rider god at Glava Panega in Moesia Inferior omits an analysis of the worshipers’ ethnicity, which would have found that several have Roman names, raising important questions (p. 202); she thinks it significant that in North African inscriptions the god’s name is typically spelled “Aesculapius” and rarely “the Greek spelling Asklepios” (presumably the Latinized “Asclepius” is meant), but this just means there were relatively few worshipers of Greek ethnicity (p. 215); and, her discussion of Asclepius’s epithets such as dominus and sanctus in North Africa is misleading because it emphasizes Punico-Phoenician parallels without properly exploring the epithets’ common use for Greek and Roman gods beyond North Africa (pp. 232-234).
Despite such issues, which do not undermine the overall value of this study, van der Ploeg has admirably filled a gap in the scholarship, though a somewhat thicker volume surveying the full range of the evidence for Asclepius in the Roman world, especially his worship by ordinary individuals in the Latin West, remains to be written. But even should such a volume someday appear, this work, which impressively draws on a large and varied collection of literary, epigraphical, iconographic, archaeological and numismatic sources to enrich our understanding of the impact of major Roman institutions on the cult of Asclepius, will continue to be worth consulting.
 Van der Ploeg’s bibliography omits Florian Steger’s 2004 study Asklepiosmedizin: Medizinischer Alltag in der römischen Kaiserzeit and its 2016 revised version, Asklepios: Medizin und Kult, now translated as Asclepius: Medicine and Cult (Stuttgart, 2018).
 Van der Ploeg omits V.M. Strocka, “Bauphasen des kaiserzeitlichen Asklepieions von Pergamon,” IstMitt 62 (2012), 199-287, questioning the extent of Hadrian’s role in this remodeling.
 A noteworthy omission is C.S. Heidenreich, Le Glaive et l’Autel: Camps et piété militaires sous le Haut-Empire romain (Rennes, 2013).