Of all the books of the Old Testament, the Book of Psalms played the most important role in Christian liturgy. A group of psalms was sung each day at the Canonical Hours, and in the course of a week, all 150 psalms were recited as part of the monastic Divine Office. Psalms were also used in the celebration of the Mass and formed an important part of private lay devotion.
The Medieval Psalter, however, was a great deal more than the Old Testament Book of Psalms and should never be viewed as simply a biblical text or purely a book for reading. The contents of psalters reflected their liturgical as well as private devotional and educational use. This paper will cover different aspects of medieval Latin liturgical psalters: their textual contents, illumination, audience and use.