In 1999 the Catholic University of America Press announced an ambitious programme to produce ‘The History of Medieval Canon Law’ in 11 volumes. The series was to bring together ‘a group of distinguished scholars to present a unified history of medieval canon law from the earliest time to 1500’. The volumes in this series offer studies organised either by period or by subject; while almost all of the volumes have been assigned authors and are now in process, the titles have been somewhat slow to appear.

The volume on Eastern canon law is the fourth volume in the series to date, and has immediately filled a huge gap. While there is a significant literature on medieval Western canon law available, augmented each year by new research and publication, this volume is thus far the only handbook of Byzantine or Eastern canon law available in English. Although there are class notes from the few courses on Eastern canon law taught in English, until now the scholarship has been available almost exclusively to those who read German or Greek (with an occasional French entry). If for no other reason, this addition to the series is extremely welcome.

The authors of the main essays are internationally recognised scholars, though their recognition in English-speaking areas may be lagging behind that accorded by the rest of the scholarly world. Spyros N Troianos is Professor of Church Law and Legal History at the University of Athens; he writes on Byzantine canon law in two essays (the first covering up to 1100, the second from the twelfth through the fifteenth centuries). Professor Heinz Ohme teaches in the Theology Faculty of the Humboldt-Universität in Berlin; he provides an essay on the sources of Greek canon law through the Quinisext Council (691/2). Hubert Kaufhold is an honorary professor in the Law Faculty of the Ludwig-Maximilians-Universität in Munich; he contributes the longest and most detailed essay in this volume, on the sources of canon law in the Eastern Churches. Susan Wessel is Associate Professor of Church History and Historical Theology at the Catholic University of America in Washington, DC; her introductory essay is on the formation of ecclesiastical law in the early Church. Unfortunately, although the author of each article is clearly identified, their academic affiliation or current appointment is not given (while, oddly enough, in the editors' introduction, those of the translators are).

The fact that this work has no real predecessors brings with it its own challenges. The original works catalogued and cited are in a dozen languages and originally written in several different alphabets. The editorial decision was made to transliterate all of these into Roman letters, but a consistent system of transliteration was not adopted. In some cases a single work or individual is referred to in different ways in the same article. Some geographical references are made according to ancient names, while other references to the same place are made according to modern nomenclature. The main articles in this collection are translated from their original languages (German and Greek), sometimes excruciatingly so. Several of these articles could have used a more careful proofreading (for example, the word ‘not’ has dropped out of two sentences in one of the articles, obviously giving the sentence an entirely different meaning).

But beyond the merely technical merits and demerits of this work, the breadth and complexity of the works surveyed are truly breathtaking. With the exception of the first article, most entries serve as handbooks or catalogues of canonical works, given in chronological order and presenting a list of printed editions with a modern bibliography of secondary treatments. The main use of these articles would obviously be to identify the works and establish something of their contents. For the principal canonical authors there is some biographical information as well. But this book is not really an ‘introduction’ to Byzantine or Eastern canon law: only occasionally does the work evaluate or describe these works, beyond simply listing their contents or giving a table of subject headings. In a very real sense, an English language history of Eastern canon law has yet to be written.

The need for such work is even more crucial because, unlike medieval canonical texts from western Europe, Patristic, Eastern and Byzantine law remains as jus vigens for the Eastern Churches. This is perhaps less evident in the case of the Eastern Catholic Church since the promulgation of the Code of Canons of the Eastern Churches by Pope John Paul II in 1990, although even here the sources or fontes of that Code, currently being compiled and soon to be published, require the information contained in this book to be evaluated, contextualised and weighed accurately. In the Eastern Orthodox and Oriental Orthodox Churches, these legal texts remain very much alive today, being interpreted and applied in contemporary cases.

With the significant exception of Clarence Gallagher's 2002 work, Church Law and Church Order in Rome and Byzantium: a comparative study, there has been little comparative work between Eastern and Western medieval canon law. This is very, very slowly changing, but it is surprising given the fact that for much of this period the legal sources are those of what many longingly refer to as ‘the undivided Church’. Even for the later period, however, the further study of the fascinating writings of the Byzantine canonists Matthew Blastares, Alexios Aristenos, John Zonaras (the twelfth-century chronicler, theologian and canonist who has given his name to a modern website on Eastern canonical sources) and most of all Theodore Balsamon can only help illuminate the similarities and differences that exist between them and their Western contemporaries, Gratian, Alexander III and the other medieval lawyer popes, Hostiensis, Johannes Andreae and others far better known to those who study the Latin Middle Ages.

Standing apart from the main entries of this book is Wessel's introductory article on the formation of ecclesiastical law. In this area, the sheer volume of scholarship is immense and prodigious, even, or perhaps especially, in English. The author wisely does not attempt to replicate the methodology of the other entries and list the various works she considers, but tries instead to give an overview of ecclesiastical law up to the period of the early Church councils. The footnotes are minimal, in some cases citing primary sources (but no secondary sources), in other cases citing secondary sources (but no primary sources) and in some cases giving no citation at all, while passing over significant and continuing scholarly controversies either with a brief parenthesis on the debates, simply presenting one side without noting that there is any debate, or dismissing the whole matter with a breezy ‘of course’. The massive literature on the questions regarding the pastoral epistles, or of church order in the New Testament, for example, is not sufficiently acknowledged. Perhaps it could not be, while still keeping the essay within manageable limits, but it is virtually impossible for a reader who wishes to delve further into some of the substantial and substantive issues raised by the author to do so, since there is no bibliography, and the sources and secondary works referenced in the footnotes are minimal.

All of what has been said, however, should only highlight what more must be done, and not detract from this ground-breaking volume. It is a worthy addition to this series, a truly significant contribution to scholarship and a vital springboard to further research that deserves to be on the shelves of every canonical library.