A service book containing the texts necessary for the celebration of the Divine Office. A breviary is often adorned with decorated or historiated initials, and more luxurious copies may contain miniatures depicting biblical scenes or the performance of the office. From the eleventh century on, the various volumes used during the Divine Office (Psalter, Antiphonal, Lectionary, Collectar, Martyrology, and others) were combined to form the breviary, which was initially only used by monks, but was popularized (in slightly abridged form) by the Dominicans and Franciscans in the thirteenth century. The breviary's contents were divided into Temporale, Sanctorale, and Common of Saints. All members of monastic orders and the clergy in major orders are committed to the daily recitation of the breviary. The contents vary in detail in accordance with the rite of the religious order or the use of the geographic area.
Michelle Brown , dkg
Michelle Brown. Understanding Illuminated Manuscripts (Malibu, CA: J. Paul Getty Museum in association with the British Library, c1994).