The study of Kaius Tuori examines the adjudicative role of the Roman emperor and its development from Augustus to the Severi. T. defines his approach against what he sees to be two major currents in the existing scholarship (2–8): the ‘formalist’ view of the emperor's judicial role as a function of his constitutional powers, an approach represented by Mommsen and the German historical tradition, and what T. calls the ‘functionalist’ view of the emperor's judicial activity as a pattern of behaviour arising from his position of supreme power, an approach perhaps best encapsulated by Fergus Millar's well-known dictum: ‘the emperor is what the emperor does’. Instead, T. proposes a ‘narrativist’ approach through ‘close reading of Roman narratives of imperial adjudication’ (9). He examines depictions of the emperor's judicial activity by historians, biographers and legal writers, as well as records of imperial judgements preserved in legal sources, inscriptions and papyri.

The Emperor of Law draws the reader's attention to the importance of the emperor's role as a supreme judge and legal authority in the Roman Empire for our understanding of Roman imperial history. To have these stories of imperial adjudication brought together in one book is useful, and will no doubt contribute to more nuanced and historically meaningful interpretations of these sources.

Other aspects of the study, however, are less compelling. The two core claims of this book are that ‘the practice of imperial adjudication grew out of the spread of the common conviction that the emperor is the final arbiter of (nearly) all things’, and that ‘the stories that circulated (and are now preserved in the historical writings of the era) were instrumental in the formation of that conviction’ (16–17). Dismissing previous attempts to define the jurisdiction of Augustus in legal and constitutional terms (105–23), T. argues that the emperor's jurisdiction developed without a clear formal basis by virtue of his ability to ‘produce the appearance of being the final arbiter and jurisdictional authority’ (114).

This questionable claim rests on the assumption that limited surviving evidence for something can be regarded as evidence for its absence. The limited evidence for Augustus and his successors acting as judges does not permit the conclusion that this happened in an irregular fashion and without a formal basis. Nor is it possible to ignore the fact that the formal powers of Augustus (imperium consulare, imperium proconsulare maius) made his executive acts superior to those of all officials in Italy and in the provinces. While one can try to argue that this was not a crucial piece of information motivating provincials to petition the Princeps, one suspects that the opposite was true. Just as Tryphera knew that petitioning Augustus in the first instance would allow her to escape the civic courts of Knidos (IG XII 3.174 = FIRA III 185), three Roman litigants in Cyrene knew that provincial courts were not authorised to investigate charges of maiestas. Instead, they were shipped off to Rome (SEG IX 8 = FIRA I 68 ll. 40–55). As illustrated by these cases, it is simply not true that there are ‘no known rules of how a case would end up with the emperor’ (194), as T. claims. On the contrary, it is possible to deduce some of these mechanisms through close analysis of individual cases. A systematic investigation of this sort has never been conducted, and one would have expected this to be a principal task of a study of imperial adjudication.

The second claim that ‘narratives’ influenced the formation of the emperor's jurisdiction is never actually substantiated with evidence. What evidence is there that the work of Suetonius ‘created a historical foundation’ for depicting the emperor as a judge and gave rise to a new general understanding of what the emperor should be (198)? Contrary to T., the rise in surviving imperial judgements from Hadrian onwards does not permit such a conclusion, since this correlates with a general expansion of the documentary record in the High Empire. A crucial part of T.’s argument pertains to the provinces and the eagerness of provincials to instrumentalise the emperor's judicial authority and thereby contribute to its rise. This point has already been argued by Michael Peachin in an article about the judicial powers of Augustus, in D. Mantovani (ed.), Il princeps romano: autocrate o magistrato? (2015), 3–59. But what, exactly, were the ‘narratives’ shaping the ‘background understandings’ of provincials about the emperor as a judge? Without any evidence to support it, T.’s core claim about the constitutive power of narratives of imperial adjudication cannot be regarded as a valid scholarly argument.

In view of the fact that T. is writing about the emperor's legal role in the Roman Empire, his selection of sources — primarily literary and legal texts produced in the city of Rome — is inadequate. Silently standing like a large elephant in the room is the great mass of evidence for Roman jurisdiction in the provinces. This inattention to the broader imperial context leads T. to make many questionable assertions, such as the claim that the Antonine emperors ‘were beginning to believe in the ideal of the virtuous ruler as the bringer of justice to their subjects’ (223, my italics). This seems doubtful, to say the least, if one considers that Roman courts had been preoccupied with the provision of justice to provincials for more than two centuries. The same can be said about T.’s uncertainty ‘how someone would know what the emperor had decided in other cases’ in view of the ‘mystery involving the existence of imperial and gubernatorial archives and their accessibility’ (256). This is hardly a ‘mystery’, in view of the copious documentary evidence for Roman judicial records and archives (F. Burkhalter, Chiron 20 (1990), 191–216; R. Haensch, SZ 109 (1992), 209–317) and for legal practitioners collecting and anthologising court judgements and citing them as precedents (A. Z. Bryen in S. Procházka et al. (eds), Official Epistolography and the Language(s) of Power (2015), 201–18; A. Dolganov in M. Jursa and H. Täuber (eds), Administration, Law and Administrative Law (2018)). Various other claims — for example, that the Antonine emperors were ‘quite clearly allowed to do as they pleased, not hindered by the laws’ (236), or that the emperor ‘as the father of the fatherland had the right to kill any member of the family at will’ (236) — are difficult to make sense of. In general, one must be wary of statements by T. where no supporting evidence is cited.

On many occasions, T.’s interpretation of the sources is incorrect or misleading. For example, Aelius Aristides (Or. 26.33, 39) is quoted as saying that a provincial petitioner ‘needs only to write to the emperor and wait for his message. There is no need to travel to petition the emperor personally, the message will come swiftly and regardless of rank, assisting everyone equally’ (196). In fact, Aristides is not speaking about individual petitioners, but about the practice of governors of forwarding queries to the emperor, the odds of which must have been very slim. T.’s interpretation of anecdotes in Tacitus and Suetonius often leads to arbitrary and impressionistic claims about historical developments, such as the implausible claim that ‘law was beginning to be a central preoccupation of the emperor’ by the Flavian period (159, my italics), or that the imperial rescript system must have been founded by Hadrian because ‘Trajan was consciously reluctant to issue rescripts in order to avoid setting legal precedents’ (211), which depends on a single dubious passage in the Historia Augusta.

Overall, considering its ambitious scope and historical claims, what T.’s study amounts to is an attempt to write the legal history of the Roman Empire in an anecdotal fashion from a very limited selection of sources (mostly literary and legal texts that explicitly mention the emperor's judicial activity) with little or no discussion of other directly relevant evidence (e.g. the evolving jurisdiction of Roman magistrates and governors) and virtually no engagement with the great mass of provincial evidence for the Roman administration of justice. Indeed, it is highly questionable whether one can adequately assess the development of the jurisdictional role of the Roman emperor without taking into account the developments taking place in the courts of the Roman Empire. As a consequence of its major flaws of approach, selection and interpretation of sources, this study cannot be regarded as a work of reference on this massively important subject. Instead, the hope is that growing awareness of the subject and its importance will serve as a stimulus for future work.