This volume presents a fresh interpretation of the origins of the Guide, its dissemination and its reception over six centuries, based on a new analysis of the twelve extant manuscripts and a collation of the variants. The authors introduce their detailed Catalogue of Manuscripts with a full discussion on the origins, patronage, authorship and production of the manuscripts. And to accompany the Catalogue, there is also a body of illustrations in which a selection of the significant pages from each extant copy is reproduced. II. The Text This en regard editio offers a new English translation of the Latin Text of probably the earliest surviving copy of the Guide - the Codex Calixtinus in the Archivo de la Catedral de Santiago de Compostela. Extensive annotations of both the Latin and English texts collate this manuscript with the other eleven extant copies. All aspects of the contents of the text are commented on - saints, relics, buildings, place-names, language, costumes, customs, history and art. More detailed discussions on the monuments are cross-refe- renced to the entries and illustrations in the companion volume, the GAZETTEER. Also included here is an exhaustive Bibliography, and a Map of the routes. This volume presents a fresh interpretation of the origins of the Pilgrim's Guide, its dissemination and its reception over six centuries, based on a new analysis of the twelve extant manuscripts and a collation of the variants.