In the tradition established by Otto Pacht and J. J. G. Alexander with their catalogues of illuminated manuscripts in the Bodleian Library, Oxford, the present publication presents all the vital information on the miniatures, marginalia and other decorations in the manuscripts of one collection. Thanks to the homogeneous nature of the Utrecht University Library's collection, this volume also serves as a much-needed study of manuscript illumination in the Northern Netherlands. Of the 181 manuscripts dealt with here, 132 are from that area. Approximately half of these are from Utrecht, the most important centre of book production in the region during the Middle Ages. A uniquely valuable feature of this publication is the large number of illustrations, most in actual size. All miniatures with identifiable subjects are illustrated, along with a choice of the minor decorations. The extensive entries are supplemented with eight indexes. Special emphasis is laid on iconography, which is indexed both by subject matter and Iconclass number.