This volume presents fourteen papers arising from a colloquium of February 2004, which was itself inspired by a seminar series of 2002–3, organized by the Centre for Ancient Mediterranean Cultures of the Institute of Archaeology of the University of Cologne, on the broader theme of media in antiquity. Both editors were participants in the preceding venture and indeed the paper by Werner Eck included in this volume reprises one already published in the proceedings of the earlier seminar (Medien in der Antike. Kommunikative Qualität und normative Wirkung, ZAKMIRA 1, ed. H. von Hesberg and W. Thiel (2003), 51–62). In turn the organizers of the seminar series have both contributed papers to this more focused project on the Tetrarchy as new political system and its representation in various media. The media considered range from literary and documentary texts of various types to coinage, architecture, and art. The regime established by Diocletian in a.d. 293, with its distinctive fourfold leadership, makes an excellent case study for examining the image propagated by the imperial court and its reflection in both public and private arenas. A better understanding of this environment also has wider significance since the events of this period provide the essential foil to, or foundation for, subsequent developments under Constantine, an emperor who continues to grip the public imagination.

After the editors' introduction, which sketches out the themes of the volume very generally, follow two chapters that have a certain genetic relationship with contributions by the same authors in A. Demandt et al. (eds), Diokletian und die Tetrarchie (2004), the proceedings of a conference held in Split in the spring of 2003. First Hartmut Leppin outlines the trends in modern scholarship on the Tetrarchy from Jakob Burkhardt in the mid-nineteenth century to Frank Kolb and T. D. Barnes at the end of the twentieth. These latter he characterizes as the chief exponents, respectively, of contrasting interpretations of Diocletian's tetrarchy as reactive and intentional. In terms of influence on the papers here, looking at the separate bibliographies for each, it is clear that Kolb's Diocletian und die Erste Tetrarchie (1987) and Herrscherideologie in der Spätantike (2001) are common points of reference for most contributors. Secondly Simon Corcoran, in the sole contribution not in German, surveys tetrarchic policy and image as reflected in imperial pronouncements, arguing that these convey the impression of energetic and ambitious legislators, whose edicts and letters are couched in much more elaborate rhetoric and take on a sense of moral urgency and self-justification. At the same time an arch-emphasis on Roman tradition sees an aggressive and unprecedented promulgation to the population of the Greek East of imperial pronouncements in Latin. Next Klaus Maresch considers the presentation of the emperors in the papyri of the period. Here the emphasis is on the imperial titulature in the formulae of oaths and dating in the documentary material. Amongst other phenomena, he draws attention to the tendency for δεσπότης to replace κύριος as the equivalent of dominus but, perhaps because it is a change in practice rather than titulature, does not reflect on the widespread introduction of consular dating into general use (an innovation for Roman Egypt), which coincides closely with the establishment of the Tetrarchy.

Patrick Brosch treats the topic of the representation of the Tetrarchy in the later Latin panegyrics. As a prelude he examines the two examples from the joint reign of Diocletian and Maximian as Augusti (X[2] of a.d. 289 and XI[3] of a.d. 291) where the Jovian-Herculian imagery is already to be found and an emphasis on their brotherhood, which is chosen rather than accidental (XI[3].7.6). Discussion of the speeches of a.d. 297 and 298 is unfortunately marred by a consistent confusion in the references, which should be to VIII(4) and IX(5) respectively. Here, when members of the college are referred to together, it is notable that both speechwriters opt to adhere to the order of precedence of the imperial college (Diocletian and Maximian Augusti, Constantius and Galerius Caesars).

In his paper on the question of the balance of innovation and continuity in the Roman army of the tetrarchic period, Thomas Fischer sensibly eschews rehashing what might supposedly be derived from the much later Notitia Dignitatum for an analysis based principally on the much more secure footing of the archaeology of the limes of the Rhine and upper Danube. The footprints of excavated forts show unmistakeable signs of the atomisation of the frontier forces into smaller units. In terms of equipment, he concludes that adoption of the so-called pilleus Pannonicus was more for symbolic effect than practical functionality. Henner von Hesberg examines new and traditional concepts of space in the tetrarchic capitals and their court infrastructure. This concentrates on circuses and amphitheatres, public baths, and audience chambers. He emphasizes how, unlike earlier examples of imperial beautification of provincial towns of origin (e.g. Lepcis Magna, Philippopolis), the anchoring of the dispersed imperial courts and their associated ceremonies in specific provincial locations transformed use of space in those cities, making real the claim that Rome, or more specifically the palatium, is where the emperor is. By contrast, Werner Oenbrink focuses on the Rome-based Maxentius as an example of an anti-type to the tetrarchic model. Here he focuses on the building programme in the centre of the city, which comprised work on the Temple of Venus and Rome, the vaulted basilica completed by Constantine, the circular vestibule for the seat of the urban prefect (the so-called Temple of Romulus), and the group of statues to Mars, Romulus and Remus, as founders of the city, erected near the Lapis niger, as central to Maxentius' legitimation.

In the next two papers Wolfram Weiser addresses the question of the image of the Tetrarchy in the coinage (with an appendix on the identity of the owner of the Beaurains hoard) and Peter Weiss similarly considers the lead seals produced by the imperial administration. Comparing the two, it is striking how the imperial quartet is regularly represented as a group, both as busts and standing figures, on the lead seals, while the obverse types of the coins remain almost exclusively individual with no more than two emperors at a time ever usually featuring in reverse imagery. Moving from the portable to the monumental, Wolfgang Thiel explores ‘Pompey's Pillar’ at Alexandria and other tetrakionia at Hermopolis, Antinoopolis, Oxyrhynchus (possibly), Luxor, and Ptolemais and Arae Philaenorum in Cyrenaica as expressions of a culture of representing the Tetrarchy in North Africa, building on an earlier article on the same subject that covered the whole of the Greek East (AntTard 10 (2002), 299–326). Of these, only the first, the last, and that at Luxor are securely linked by epigraphic evidence with celebration of Diocletian and his colleagues. There remains a certain danger of circularity in the argument in the other cases, though the pattern is indeed suggestive. Eck's paper addressing the idea of Diocletian's regime as reflected in the texts and images of public monuments follows on naturally. Here he explores numerous examples of the ubiquitous devotional formula d(evotus/icatus) n(umini) m(aiestati)q(ue) e(ius/orum), showing that, even where only a single dedication survives, we may regularly assume that it formed part of a pair or group honouring the imperial college together, as exemplified by the porphyry statue groups preserved in St Mark's Square in Venice and in the Vatican. The paper of his fellow editor, Dietrich Boschung, on the tetrarchic regime as message of visual media, actually confines itself largely to the best preserved genres: statuary and relief sculpture. The Venice and Vatican groups feature again, as well as the arch of Galerius at Thessaloniki, the vicennalia monument from the Roman Forum, and, more unusually, the Arcus novus (demolished in 1491), with its elements cannibalized from the Claudian Ara Pietatis and the Aurelianic Temple of Sol. In these last two monuments he reads a nod, in the face of the opposite reality, to the nostalgic idea of Rome as the centre of the empire and an appeal to the traditions of the earlier imperial period.

With Katja Sporn's paper, exploring the contemporary reception of the tetrarchic visual discourse, the discussion moves from the public to the private. She poses the question of whether the imperial self-representation had any resonance. She surveys sarcophagi, mosaics, wall-painting, private statuary, ivory carving, and miniature representations of the imperial image in glass and on lamps. Her conclusion is that the impact is distinctly limited, in contrast with that of imperially sponsored art in the Augustan period, which forms her counterpoint. The volume ends with an essay by Hartwin Brandt on the Tetrarchy as portrayed in the literature of the fourth century, which, he acknowledges, nicely complements the paper by Heinrich Schlange-Schöningen from the Split conference on the reception of Diocletian under the Constantinian dynasty. This interesting discussion could have been made more accessible had the reasonably extensive passages of Greek and Latin authors been provided with a vernacular translation. A contrast to the predictable negative impressions conveyed by hostile Christian contemporaries, such as Lactantius and Eusebius, is the attitude of the late fourth-century anonymous author of the Historia Augusta to whom Diocletian was ‘the father of a golden age’ (vita Heliog. 35.4) and he and his colleagues ‘four rulers of the world … of one mind with regard to the commonwealth’ (vita Cari 18.4).

The undoubted strength of this volume lies in the tight thematic connection between the various papers. However, the ‘light touch’ approach to editing that has been taken does the volume overall a disservice. As a result, there is little feeling of dialogue between contributions, despite many points of connection, of which one obvious symptom is the repetition in different papers of images of the same artefacts: the porphyry group in Venice (125, 343, 352), the similar group from the Vatican (341, 356), and the same section of the arch of Thessaloniki (263, 387). The situation is exacerbated by lack of an index of any sort. Moreover, given the various overlaps, this is one multi-authored volume where a consolidated bibliography, at least of the works commonly enough cited to be given abbreviated forms separately in each paper, would actually have been helpful rather than simply fashionable. Again, although contrived links are to be avoided as a rule, in the absence of abstracts, a concluding section that highlighted the points of agreement and contrast between the separate contributions would have benefited the reader. Thus an opportunity is missed to reflect on the implications of aspects that might seem surprising, such as the fact that there is not more examination of Diocletian's palace-mausoleum complex at Split or Galerius’ equivalent at Romuliana (Gamzigrad). That these do not feature more prominently underlines the fact that these monuments do not celebrate the collective and that, for all the emphasis on fictive brotherhood and parentage in the tetrarchic regime, in death individuality reasserts itself. On balance, despite the shortcomings in its publication, this collection is certainly worthy of serious attention and will repay those persevering readers who take the trouble to explore it in detail.