The book under review pertains to the renewal of studies dedicated to the Roman historian Cassius Dio, currently the object of a great many publications.Footnote ¹ Like the majority of these studies, B. focuses on the historian's political thinking. Meanwhile, she adopts a fresh approach by wielding the ancient concept of civilitas, by focusing her analysis on political practices and the nature of the relationships between principes and senatorial aristocracy. B. proposes to assess the continuation in the third century of the theoretical political concept of civilitas defining the ‘good emperor’. At the same time the volume analyses the place of this concept in Dio's historiographic project with a view to establishing the extent to which it operates in his accounts of princeps–Senate relations and whether contemporaneous events impacted on its use. The 633-page synthesis, resulting from a meticulous investigation that balks at none of the snares lurking in a work preserved by indirect tradition for most of the imperial reigns, demonstrates a rigorous approach. B.'s methodology attends to the lexicon and the political practices described, but it also seeks to confront Dio's viewpoint on historical realities, such as that they can be reconstructed through the available documentation – literary, epigraphic, numismatic –, in order to assess the singularity of Dio's discourse, if not his reframing of events to fit with his historiographical aims.

The first chapter dedicated to the state of the art brings out the ambiguity of a concept that, according to ancient authors, can refer just as readily to moral values as to political praxis, and which has been studied more with reference to Latin than to Greek literature. In the context of Cassius Dio, relevant research has shown that this notion pertains to the dialectics between senatorial libertas and autocratic principate. One of the major stumbling blocks in the study – Chapter 2 – is the Greek terminology for civilitas and princeps civilis: a Greek equivalent of the substantive does not exist, and that means using adjacent but polysemic terms, periphrases even, denoting a behaviour respectful of Republican institutions and traditions. These include the Greek adjective demotikos, rarely utilised in its substantive form, but detected by B. in eight instances up to Pertinax to refer equally to emperors and to imperatores of the end of the Republic, along with the adjective demokratikos, used with forms derived from it in seven instances to qualify the emperors. The analysis of the context makes it possible to refine the lexical meanings correctly and to identify the political practices associated with the concept of civilitas. The concept appears from the end of the Republic and is in use under the first emperors, Augustus and Tiberius, the latter attended with the most numerous mentions of civilitas: this insight helps to understand the transition between the Republic and the Principate in the two respects of political analysis and of institutional analysis. B. thus analyses the governing principles advocated by Maecenas in Book 52 (Chapter 3) in the framework of (1) the relationships between princeps and senators, (2) justice, (3) imperial cult and cults, (4) games and spectacles and (5) relations with the troops: the use of the notion is patently associated with constitutional mixis and signals the reworking of the Platonic concept of a mixed constitution in which a new politeia amounts to a balanced exercise of power by principes and senators. Having established the terminology and the political practices associated with the concept of civilitas, which bring to light its defining role in the inception of the Principate, B. seeks to verify the workability of the concept in the accounts of the imperial reigns, to cast light on the dovetailing between the biographical and the thematic principles. In the accounts of the Julio-Claudian and the Antonine reigns, barring Commodus (Chapter 4), Dio organises his material according to themes revealing the government's positive or negative praxis, headed by crimen maiestatis. Although Dio's analyses broadly conform with literary tradition, it should be noted that the author points to a more measured judgement of Trajan, whose craving for military glory denies the granting of the civilis label. Conversely Marcus Aurelius is exalted as the archetypal princeps civilis, bringing to a close the cycle Dio rated as a golden age. In the last chapter (5) the aim is to measure the impact of contemporaneous events on Dio's project and his application of the concept of civilitas to Roman history. This perspective accounts for the decision to start this last chapter with Commodus: there is good reason to believe that Commodus’ reign, under which Dio began his senatorial political career, was the seedbed of his thinking on political practices, the relationships between princeps and senators and the idea of civilitas as a grid of political analysis. Commodus’ relationships with senators, the awarding of disproportionate honours and self-legitimisation strategies set a contrast with Marcus Aurelius and deny his son any claim to civilitas. While the findings on Pertinax include the single mention of civilitas connected with a contemporary princeps, Dio's view of Septimius Severus is ambivalent: on the one hand, he acknowledges his respect for senatorial status, notably for never putting to death a senator on economic grounds; on the other hand, he censures him for his dynastic policy, absence of clementia and special treatment of the army, so that Dio is unlikely to have listed Septimius Severus in the principes civiles series. His views are more clear-cut when it comes to Caracalla, guilty of a political purge after the murder of Geta, of increasing fiscal pressure and of militarist policies; to Macrinius, who epitomises the antithesis of the princeps civilis, with his non-senatorial origins and the modalities of his investiture in full disregard of senatorial competences; and to Elagabalus, whose ill-will against the senators appears to invite a ‘snobbish’ reaction from the senator-historian. Dio conducted his second consulate (229 ce) under Severus Alexander, but his familiarity with his reign does not impair the author's critical capabilities; prosopographical analyses of the political staff confirm Severus Alexander's conservatism, which would vouch for the image of a civilis princeps, but the troops’ role, notably in the process of the princeps’ investiture, annulled senators’ authority.

An ample conclusion underlines Dio's viewpoint on imperial politeia and underscores both its coherence and its originality. A senatorial ideology runs through the narrative and defines a mixed constitution founded on the guarantee of social hierarchies and the senators’ association with the exercise of power; in this politeia, to be a civilis princeps is to uphold the respect of traditions safeguarded by the Senate. Dio sets forth a novel version of the concept of civilitas that is defined by his political experience under the reigns of Commodus and the Severan emperors and structures his account of the imperial reigns. In the conclusion B. also addresses the much discussed matter of the dating of Dio's Roman History and favours a dating that sets its origin at the 204 Secular Games, a dating that B. deems consistent with the demonstrable influence of Dio's political experience on the drafting of his work.

The volume offers a fresh approach to Dio's political thought, which has rarely been given such an exhaustive reading. Whereas there has long been no doubt that the historian advocates a moderate monarchy, B.'s input is based on her development of the nature of this moderate monarchy, via the confrontation of Dio with parallel sources and a rigorous internal analysis. Scrutinised through the lens of the concept of civilitas drawn from political philosophy, this monarchy would have the princeps and the senators sharing power in a balanced way and upholding the respect of traditions inherited from a Republican ‘libertas’ ill-used in Dio's days by the dominant power of the military. The book is well produced, and the bibliography is exhaustive. Substantial indexes of sources along with protagonists and concepts enable readers to make the best of the research. The work conclusively displays the cohesion of Dio's historiographical project and will be an equally valuable guide to readers of Dio and to historians of the High Empire.