The Royal Abbey of Saint-Denis was founded in honour of Dionysius, one of seven missionaries sent from Rome to Gaul around 250. It grew to be one of the most powerful monasteries in western Christendom and enjoyed a central position in French history as the first Gothic abbey, royal necropolis, and place of origin of the chronicles of the kings. This is a study of the music and ritual at Saint-Denis from the sixth to the sixteenth century. It is based on an examination of the liturgical books and archival sources relating to the abbey, in particular the surviving service-books, which tell us much about the history of the music and of the Divine Office at Saint-Denis. Anne Robertson also looks at the tropes and sequences proper to the office for Saint-Denis, provides information on the performance practices, instruments, musicians, and liturgists from the abbey, and offers an account of the history of the liturgy from the Council of Tours in 567 to the pillage of the abbey by the Huguenots in 1567, thus explicating the extant liturgical codices from Saint-Denis. For the author the ritual and history of the abbey is also inextricably linked to the reconstruction of its various buildings, the decorations of the church, even the monks' ambitions. This is a fascinating and wide-ranging study of this extraordinary institution.