The two themes brought together in this volume - the canon law and the liturgy of the early mediaeval Latin Church - have close links. In the book particular emphasis is given to the Irish ""collection canonum hibernensis"" and its many derivatives, to works from Carolingian Salzburg and 11th-century Southern Italy, and to liturgical collections. The whole attempts to show the need for liturgiologists to be aware of the riches in mediaeval legal sources, and for legal historians to take account of the wealth of liturgical material that is a principal ingredient of the law of the Church; and demonstrates how much one field can contribute to understanding the development and to the dating of the other.