Canon law collections are an important source not only for the history of church law in the Middle Ages, but for ecclesiastical history in general. From the beginning of the genre around the year 500, many of these collections were introduced by prefaces. These often emphasise the excellence of the dedicatee and the unworthniness of the compiler, while none the less hinting (more or less subtly) at the merits of the latter. More importantly, many compilers in their prefaces go beyond such niceties to reflect on the nature of the law, the role of ecclesiastical judges, the mutability of some (but not all) ecclesiastical laws, the relation between human and divine justice and other fundamental issues of law and theology. Reading a large number of them in comparison provides a fascinating approach to the development of canon law in changing circumstances.

By making available translations of a large number of such prefaces, Robert Somerville and Bruce Brasington in 1998 greatly facilitated access to these sources, and provided a very useful resource for teaching canon law history. This new, enlarged edition contains three new texts from the thirteenth and the early fourteenth century, so that one can now study no less than thirty-eight different primary sources ranging from the preface to the Dionysiana of c. 500 to the bull of promulgation for the Constitutions of Pope Clement v of 1317.

After a general introduction (pp. 1–16), the main part of the book is largely arranged chronologically. Every single chapter contains fine translations of six to ten texts, with short but very useful introductions. Brief as they are, they provide the necessary historical context and make the canon law issues in question accessible to non-specialist readers. A ‘Bibliographical essay, 1997–2017’ (pp. 209–15) provides an excellent guide to the specialised research published since the first edition appeared; it begins with a useful list of online resources (pp. 209–10) while the remaining five and half pages effectively serve as a review essay of some two dozen monographs. The ‘essay’ should be read in conjunction with the individual chapters which have largely been left unchanged from the first edition. Occasionally, therefore, the ‘essay’ and the individual chapters are slightly at odds (compare, for example, p. 113 to p. 213 n. 23) and some notes made more sense in 1998 than today (p. 98 n. 13).

The translations are very good and help the reader to make sense of sometimes difficult texts. For good reasons, they do not follow the original Latin too slavishly. In the case of the opening lines of the preface to the Polycarpus (p. 110), however, a short note as to why the translation deviates from the edition it cites would have been welcome. (The exact wording matters, not least because the opening lines are crucial to establish to whom the collection was dedicated and also when the Polycarpus was compiled.) For the famous Rex pacificus by Pope Gregory ix it may have been worth mentioning that the register version of the letter shows that it was sent to a larger number of recipients, not only the masters at Bologna (as Friedberg's edition, and hence the translation at p. 203, could suggest). Yet these minor quibbles are mainly a reminder of something Somerville and Brasington modestly pass over in silence: how difficult it is in many cases to establish the Latin base text for these documents. For, in the absence of critical editions, one often has to compare a number of both manuscript and printed versions to establish with some certainty what the original Latin may have been. The authors spare the reader the details of this sometimes cumbersome work, and instead present very good translations based on the sound editorial choices they have made.

The result is an elegant book which can be used as a primary source reader, but likewise be read as a short introduction to medieval canon law history. Like the first edition, it will be very welcome to anyone teaching canon law history at university level. Specialists and non-specialists alike will profit from the new, enlarged edition of this wonderfully useful book.