This is an important and timely volume, in light of other recent publications on various aspects of Byzantine law, both secular and ecclesiastical. Wagschal's book is a carefully-documented, critical and rigorously argued study of the evolution of canon law in its broader context from the late fourth century (the canons of the council of Constantinople in 381) to the later ninth century, and represents a sophisticated and innovative analysis of the ways in which canon law is far more than just the disciplinary code(s) of the eastern church. Challenging established and often outdated models of the decline of both the theory and the practice of jurisprudence in general and of ecclesiastical lawmaking in particular in the Byzantine world, the book argues to the contrary that east Roman canon law reflects a coherent and sophisticated legal tradition that has been both misrepresented and misunderstood. In the process of describing the growth and development of the canonical tradition, Wagschal analyses the form and content of the canonical corpus, the language, rhetoric and interpretative strategies deployed by the canonists, questions of definition and the establishment of an appropriate technical vocabulary, the question of systematization across the canonical corpus, the nature of the educational background and knowledge of the canonists and the related issue of “professionalization,” as well as the relationship between secular and canon law. In concluding his analysis, the author notes that Byzantine canon law is marked by three key characteristics: an emphasis on laws, not “law”; an emphasis on substantive justice, that is to say, that justice must be done (and seen to be done), rather than simply that a formally correct legal solution had to be found; and the importance of tradition (yet not without the possibility of accepting modification or change). Perhaps most importantly, he is able to argue—persuasively—that Byzantine approaches to canon law as well as law more broadly reflect a very different conceptual world from that of the modern commentator, and that we need to begin from a very different intellectual perspective from that usually assumed if we are to grasp its centrality and significance. This is a point that applies to much more than just the law, of course. In sum, an excellent study that will do much to make a wider scholarly readership aware of the need both to integrate “the law” more effectively into the study of medieval east Roman culture in general, as well as to challenge many assumptions about how to understand the law, jurisprudence and the legal textual traditions of this dynamic medieval culture.