This book is a synthesis embracing over a millennium of the history of Western liturgical sources; it also is a manual of introduction to these sources. A detailed chapter is devoted to each type of book, each book intended for a specific form of celebration and for a specific celebrant. The crucial transition from oral practice to the use of the written document is discussed as well as illustration of liturgical books. The first chapter reviews the works of scholars who from the sixteenth and seventeenth centuries to our own day have studied the manuscripts pertaining to the first thirteen centuries. The conclusion treats of the relationship between medieval histry and liturgy suggests new methods of research and underscores the fruitfulness of an interdisciplinary approach.