Monastic liturgies are difficult to access. Certainly, plenty of service books survived, but their majority comes from a period when a comprehensive scope and detailed rubrics were something that most liturgical books still lacked. Moreover, such books practically never refer to their mother institutions. Monastic houses were far more numerous and changed their customs more frequently than cathedral chapters. In the age when chapters began to compile detailed and comprehensive books, monasteries were already declining or being reformed according to international standards. This is why source material that is both informative and reliably refers to mother institutions is so invaluable from the perspective of liturgical history.
Customaries are normative texts regulating monastic communities in terms of liturgy and beyond. Liturgical evidence is, however, often hidden or somewhat disguised in them. This is why their excellent and extensive edition, the Corpus Consuetudinum Monasticarum, could not have been fully utilized in this respect. Now the obstacle is removed by the present volume, a thorough and systematic work of our Usuarium team member Ábel Stamler that offers both an indispensable tool for researchers, and a mental map for the fields of worship in the monastic programme of life.