Exactly one decade after its acquisition by Harvard University's Houghton Library, a somewhat battered 14^th-century Liber ordinarius from the abbey of Nivelles (a prestigious house of aristocratic canonesses in the heart of present-day Belgium) is celebrated in this collective volume. For a very long time the genre of the Liber, a type of handbook that describes the order of the liturgy, was thought of as perhaps the most routine (some would say outright dull) of witnesses to ritual and prayer service at religious institutions of the later medieval period. However, the last two decades have seen a drastic change in this perception, thanks to a number of publications that for the first time have dug below the surface of these enigmatic manuals. Among other things these studies have revealed the genre's potential to yield a wealth of information on the lives of the men and women who used them: their liturgical and cultic practices, their experience of sacred space, their social positioning, and also their self-understanding.

While the present book inserts itself in a crowded bibliography, the multifocal and multidisciplinary approach, the commendable attention to context, and the outstanding quality of most of the contributions instantly make it a key reference. The introduction by the two editors successfully makes the case for devoting to the »Nivelles Liber« a collective research effort of this scope by specialists (many of whom are at the top of their field) from a wide range of disciplines. Among other things it highlights the relevance of this joint effort to unpicking the manuscript's complex relationship to the cultic tradition of patroness St Gertrude, the use of sacred space at Nivelles by women and by men, and the canonesses’ liturgical practices. The introduction likewise canvases the Liber's significance as a record of tensions and shifting relations between the abbess and her community, and between the community and its secular environment.

In the first of five thematic sections, Jeffrey F. Hamburger and Albert Derolez expertly discuss the codicology of MS Lat 422, its palaeography, and its decoration, and in doing so make a most valuable addition to the current state of research regarding the material and technical aspects of the genre. The second section will likely appeal to the widest readership on account of its focus on historical context and also because of its clarity of argument. Eva Schlotheuber’s chapter on the history of Nivelles abbey from its seventh-century origins until the later Middle Ages offers a longue durée perspective on the development of this female community over seven centuries. That by Walter Simons reveals the permeable boundaries between different experiences of the religious life for women via a comparative study of the Nivelles canonesses and their Beguine neighbours. Finally, Rowan Dorin’s study takes the Liber's diverse contents and its seemingly chaotic organization, and deftly links it to a context of recurrent tensions between the Nivelles abbesses and their subjects in the later 13^th and early 14^th centuries.

The third section of the book deals with cultic practices, and starts off with Bonnie Effros’s analysis of embattled Abbess de Bierbais’ (d. 1293) translation of the relics of St Gertrude as a means to symbolically end an era of disruptive clashes with the canonesses. Margot Fassler’s contribution sets the references in the Liber to the cult of St Gertrude against the background of long-standing liturgical and hagiographical traditions at the abbey. These two richly documented and carefully argued chapters contrast with Alison Beach’s succinct contribution on the election and investiture procedure of abbesses as it is described in the Liber.

The fourth section adds a liturgical dimension to the insights offered by Effros and Fassler. Louis van Tongeren discusses Holy Week as celebrated at Nivelles, and Charles Caspers explores the Nivelles canonesses’ religious processions and what these tell us about their view of the surrounding lay society. Finally, the fifth section brings a spatial dimension to the discussion in the form of Gereon Beucker’s discussion of the architecture of the abbey church, and Andreas Odenthal’s on the sacred topography of the abbey site as revealed through the Liber.

In the final part of the book Thomas Forrest Kelly looks at the Liber’s relevance for reconstructing the abbey's church personnel, while Virginie Greene and Hannah Weaver assess the use of the French vernacular at this stage in the community’s existence. The work closes with a welcome and carefully executed edition by Hamburger and Schlotheuber of selected documents from the Liber. These excerpts reveal the sheer abundance of information that is contained in the statutes, regulations, liturgical instructions and historical accounts in the manuscript and will hopefully inspire readers to further exploration.

This publication, which adopts a similarly unassuming (if tasteful) layout as its object of interest, deserves close attention from any researcher in the field of late medieval religious identities and practices. It is an outstanding collective achievement and its methodological approach is exemplary. The next step, this reviewer suspects, will be to bring gender to bear on the Liber’s contents, to explore the unusual accessibility and relevance of the manuscript to both male and female users at late medieval Nivelles.