In 212, Caracalla granted all inhabitants of the empire Roman citizenship in what may be considered a momentous change. Earlier, citizenship had been a coveted privilege, used to reward allies, but the edict would have bestowed this gift to all. To borrow terminology from international law, Rome moved with a single stroke from a personality principle to an area principle in terms of citizenship. Because this would presumably meant that the expansion of citizenship would have resulted in a corresponding expansion of the group entitled to use Roman law, the edict has been the object of much interest among legal historians. While the existence of the edict itself is attested by numerous sources such as Ulpian and Cassius Dio, there has been long standing controversy over its impact and the Constitutio Antoniniana (hereafter „CA.“), as it has been called, may well be considered one of the major controversies in Roman legal history.
The work under review sets out an ambitious aim of resolving this long-standing controversy by examining the impact and effect of the CA in Roman law and society. Until the pioneering studies by Sasse and others on the so-called Bürgerschaftspapyrus (P. Giss. 40), which allegedly contained parts of the text of the edict, the CA led a shadowy existence. Perhaps due to the 1800-year anniversary of the CA, this obscurity has been broken by a flurry of new studies. These have given the CA a new look from various points of view, from papyrological analysis to discussion on legal pluralism in the Roman provinces and the changing role of citizenship.
Compared with other works of this renaissance of studies on the CA, Besson’s book presents a comprehensive approach that seeks to combine results from multiple fields and traditions, presenting what may only be described as an attempt at a definite result of the extensive debate. While little new source material on the CA has been revealed since Sasse, the scholarly surrounding has undergone an almost complete change, with a new generation of scholars approaching issues of law and citizenship in the provincial context with new tools and theoretical frameworks, rejecting the antiquated notions of center and periphery with a pluralistic, processual and contextual conception of law. Besson seeks to integrate the new approaches with a thorough analysis of the sources, combining the law in action with the law in books, to borrow the old legal realist credo.
This is a vast undertaking, but Besson has managed to complete it, in itself a considerable achievement. In doing so, he covers a lot of ground, from the analysis of the papyri to onomastics, taxation and family law. The book is divided into four main sections, beginning from the sources of the CA and continuing to grants of citizenship, legal procedure and conflict of law and, finally, to substantive law and legal institutions. In the three last chapters, there is a coherent focus on the numerous consequences of the CA in various fields and their analysis.
The first main chapter consists of an outline and analysis of the sources of the CA and its impact (pp. 23–104). Thus the chapter combines a fairly strange combination of items, from the legal and historical sources of the CA itself and the P. Giss. 40 to the survey of the onomastic changes taking place in the provinces, namely the spread of the name Aurelius. This well-known phenomenon of newly enfranchised citizens taking the name of the emperor who gave them citizenship is used to estimate the date of the enactment of the CA and the spread of its influence in the provinces. The piece by piece analysis of the papyri and other sources of the CA are solid work with little imprecisions, but they cover mainly already well-known territory. Though the spread of Aurelii has been noted already earlier, Besson adds to this a very useful analysis of the times when the Aurelii begin to appear and uses that to trace when information about the edict spreads around the provinces.
The second chapter examines grants of Roman citizenship in the provinces and its impact, arguing that the CA resulted in a vast expansion of citizenship from the roughly 30 percent preceding it (pp. 105–182). Although he explains how the issue is still disputed and unclear, the lengthy historical detour of the various individual and group grants since the Republic takes a long time before getting to the point of the CA and the change that it brought. What it does bring forth is the importance of citizenship and the anxieties, claims and counterclaims that disputes over citizenship and the rights it brought in legal procedures. Before the CA, citizenship was a privilege that for many was gained through military service and which brought many advantages both social and fiscal. However, Besson argues that fiscal benefits from new grants of citizenship were most likely minor and the economic consequences were not a major factor in the CA.
The third chapter takes up yet another major issue that has been the subject of much discussion, the application of Roman law in the provinces and the possibilities of legal pluralism. The controversies over choice of law, relationship between local and Roman courts and the agency of provincial and Roman actors is a rich field where the potential impact of the CA would potentially be visible, because in theory only Romans could resort to Roman law. However, the broad survey of sources and cases before and after the CA mainly serves to illustrate the fluidity of the situation and the leeway given to litigants, but also the growing influence of Roman law in the provinces while maintaining the continued existence of local law and courts.
The fourth and final main chapter is dedicated to substantive law, focusing on legal institutions particular to Roman law. Again technically, Roman forms of marriage and testament were available only to Roman citizens and thus following their spread would allow to hypothetically trace the spread of Roman law after the CA. As has been shown in earlier studies, different forms of legal status such as Latin rights and slavery continued even after the CA, but Besson sees the spread of exclusively Roman legal forms as a potential evidence of the spread of citizenship.
On the whole, this is a good book, one that has demanded an immense amount of work shifting through source material and secondary literature. As such, it provides a valuable synthesis of the state of the art and a convincing picture of the impact of the CA. Although many of the issues have been investigated earlier, the book’s main contribution is this general picture, where the connections between the spread of citizenship and the substantive law regarding marriage and testament become clear. The collection of sources and their analysis as well as modern literature is up to date and relevant and will be very useful. However, the book may have been improved by scaling back some of the historical background and by focusing on the changes one does see. The present reviewer found himself often to be reading this in the same way one does with official reports, beginning from the conclusions and working one’s way back through motivations and finally the sources. There is a logic and clarity in the current arrangement, one that possibly derives from the origins of the book as a thesis, but it overshadows somewhat the indisputable achievement of the work at large.
 Alex Imrie, The Antonine Constitution, Leiden 2018, and Clifford Ando (ed.), Citizenship and Empire in Europe. 200–1900, Stuttgart 2016, are the most recent to appear.
 Kimberley Czajkowski / Benedikt Eckhardt / Meret Strothmann (eds.), Law in the Roman Provinces, Oxford 2020.