This imposing book, in line with the works of E. Flaich and J. Szidat, among others, is the result of a doctoral thesis defended in Lille in 2016 and offers readers a penetrating analysis of the phenomenon of conjuration and usurpation. The latter are the result of a break in the consensus enjoyed by a Princeps or the prelude to an enthronement that will eventually win the support of all the parties involved (populus, Senate and armies), although in both cases a great deal of blood will be shed. Usurpation was the main form of access to power and the first danger faced by an emperor who sought to protect himself by all means. To do this, S. examines the question of the conquest and then the maintenance of power by Roman emperors over the long term, from Octavian-Augustus to the fall of the Severan dynasty.

However, the book does not only present an exhaustive list of conjurations, with their frequent corollaries, usurpations, whether successful, aborted or nipped in the bud. S. describes in great detail the gradual establishment of practices and traditions, different each time and adapted for the occasion, but in no case founded on a legal basis, which lead to usurpations or on the contrary contribute to their failure. S. also addresses the question of the innovations, taken up and adapted according to the circumstances, which feed these exempla, whose effectiveness is proven over time. In other words, S. highlights patterns that are repeated: codified gestures, words and actions, with a view to obtaining consensus through persuasion or coercion, hence the title of the book, whose English translation is ‘holding a wolf by the ears’ and which refers to Tiberius (Suet. Tib. 25.1). Subsequently, once power has been conquered, S. discusses the process of legitimisation in order to retain it and be obeyed over time, which requires recognition by three entities: the Senate, the people of Rome and, above all, the armies, whether praetorians or provincial legions, without which the emperor does not have a consensus and risks being the victim of usurpation.

The study is divided into three main parts. The first deals exclusively with the Julio-Claudian period, during which the models, many of which date back to Augustus, were developed and used by other emperors or pretenders to the Empire. If, little by little, the armies were to acquire a decisive weight in the struggle for power, which was to go to the strongest, Octavian-Augustus always took care to legitimise his achievements through the populus and the Senate. He used omina as well to consolidate his position and make it last: the consensus initially based on force would eventually become freely accepted. Moreover, he concentrated all the powers that placed him above other citizens while giving the impression of not seeking these honours, which are bestowed on him almost ‘unwillingly’. The Princeps also made limited use of the lex de maiestate in order to carry out, if necessary, selective eliminations to remove his rivals, against whom he showed severity or clemency. On the other hand, his successors, who did not have to conquer power or make a decisive contribution to the maintenance of peace, ensured that this legacy was preserved in various ways. The remainder of this first part therefore focuses on how Tiberius, Caligula, Claudius and Nero did this, despite having assets such as a popularity based on blood kinship with Augustus, when they did not rule in permanent mistrust despite association or adoption by their predecessor.

The next section covers more specifically the year of the four emperors and the Flavians, following Nero's loss of consensus leading to his elimination. This marks an important caesura in so far as Vespasian eventually prevails after a civil war, a hated experience that was thought to be definitively over. Moreover, like Galba, Otho and Vitellius, he did not belong to the Julio-Claudian family. This obliges each of them to elaborate discourses, reflected in the monetary issues, which were inspired by the deeds of Augustus, to whom they tried to relate in one way or another, in order to justify their victorious usurpations until the final success of Vespasian. Then, after an analysis of the practices of the Flavian dynasty, which were inspired by those of their immediate predecessors, S. discusses the fall of Domitian, as the victim of a conspiracy, and the elevation of Nerva to the purple, who managed to avoid a civil war by the judicious election of a successor in the person of Trajan, so as to obtain the consensus of all.

The last part focuses on the Antonines and the Severans. This period is characterised by its greater stability, to which the princesses of the domus Augusta contributed more decisively than in the past, as they took part in the transmission of dynastic legitimacy. In fact, until the reign of Marcus Aurelius, no usurpation and very few trials for maiestas are recorded. It was not until the attempt by Avidius Cassius (ad 175) that the first signs of contestation appeared. This trend became more pronounced following the first hereditary succession within the dynasty, which until then had favoured adoptions for lack of male descendants, with the ascension to the throne of Commodus, whose form of government, beyond the clichés of literary sources, had points in common with Caligula, Nero and Domitian. In fact, after his assassination, a period of civil strife began, which ended with the victory of Septimius Severus and the establishment of a new dynasty that lasted until ad 235, which marks the end of the study.

S.'s careful work reveals various arcana imperii, unwritten rules of power management, in order to ensure its continuity in the face of internal threats. To this end, the lex de maiestate proved to be a formidable instrument for carrying out selective eliminations among the capaces imperii and the members of the domus Augusta, while victories on the battlefield, the granting of donativa to the troops or congiaria to the populus made it possible to win or retain their support. Similarly, appointing heirs, sometimes through female relatives, also helped to consolidate their position by ruling out any possibility of conspiracy or usurpation. At the same time, it should be noted that the weight of the armies became more and more important, and in the event of a loss of consensus, they managed to impose a candidate, admittedly from the Senate, but without the High Assembly or the populus, which were necessary to ratify his legitimacy, as they were less and less able to oppose the will of the soldiers. Conversely, neither the people nor the Senate could achieve their aims without the troops stationed in Rome or in the provinces having a say. The permanent use of literary and numismatic sources, without neglecting epigraphy or papyrology, as well as the great care taken to reflect on the validity of the information they reveal, should also be highlighted. It is regrettable that there is no specific study of the terminology of conjuration and usurpation in Latin and Greek, so as to appreciate their semantic significance and nuances. It is also worth noting, on p. 62, the error relating to Varus’ defeat by Arminius’ coalition of Germans and not Ariovistus’ Suevi. However, this in no way detracts from the quality of the book, which does not omit any fundamental bibliographical references and thus offers an original view of power in the imperial period as exercised from inside the imperial palace, while also giving a voice to the defeated, in order to understand their motivations and the reasons for their failures.