The liturgical principles of the Cistercians were grounded, as with all other aspects of the Order, in the strict observance of the Rule of St Benedict. The singing of the psalms was central to Benedictine monasticism, and Benedict devoted several chapters of his Rule to an explanation of how the complete Psalter could be recited each week by dividing its contents between the various services of the day and night office. By the eleventh century, several abbeys under the influence of Cluny had sufficient endowments to enable their monks to pray and chant all day, leading to a perpetual cycle of worship which paid less attention to the spiritual reading and manual labour with which Benedict had balanced the life of prayer. It was in liturgical matters that the early reformers could most easily perceive decadence in the Cluniac congregations: the chief intention of the founders of Cîteaux was not to establish a new religious Order so much as to strip out the many liturgical accretions which had filled the monastic day, and thereby to maintain a more even balance between ora et labora. Their adherence to Benedict’s prescriptions was very literal, and understandably attracted derision from some quarters, notably in Abelard’s letter to Bernard.

When Robert and his twenty-one companions left Molesme in 1098 to establish the New Monastery that would later be named as Cîteaux, we may assume that they took with them the various liturgical books, vestments and vessels that they would require for worship. When Robert was recalled to Molesme the following year, his companions were allowed to retain all of the equipment he had brought with him (his capella), with the exception of a breviary which they were instructed to return to Molesme after making a copy. A psalter written in Arras which Robert had owned in Molesme was among the books kept at Cîteaux, but a note added to it later records that its calendar and litany were unusable for the rite of the New Monastery. There is no way of knowing precisely how services were ordered in the very early years, but it was under Stephen Harding’s abbacy (1108/9–33) that major revisions were made to bring the liturgy in use at Cîteaux under a more systematic and uniform structure, primarily to ensure that the newly established daughter houses followed the same practices as the mother house.