The book I is a collection of liturgical texts (Masses, homilies, sermons) in honour of the Apostle; the most famous is the sermon Veneranda dies, where much news is given of the meaning of the pilgrimage of the Middle Ages.

Book II collects the 22 most famous miracles of Santiago the Elder which occurred on the route of the pilgrimage, at sea and in other far-off lands.

Book III is dedicated to the transfer of the body of Santiago from Jerusalem to Galicia. This is the well-known text of the Translatio, which narrates the voyage of the remains of the Apostle after his death, stopping at Iria Flavia before being buried in the temple of Compostela.

Book IV is dedicated to the adventures of Charlemagne in Spain. This is a literary text related to the medieval “Chanson de Geste”, which tells of the struggle of the Frankish emperor and heroes such as Roldan against the Muslim, the discovery of the tomb of Santiago and the construction of the city of the Apostle and the liberation of the Way of pilgrimage.

Book V is more well-known because it describes the Ways of Santiago in France and Spain, the route of pilgrimage created between the X and XII centuries in order to reach Compostela. The text provides abundant news of the sanctuaries, towns, people, meals and dangers faced by the pilgrim. It also describes the Compostela of the XII century and its Romanic Cathedral.

A relevant section is the musical appendix of the Codex. The creation of polyphony began in the city of the Apostle after two centuries of searching in the principal musical chapels of France. The music of the Liber is included in a collection of twenty-one pieces which represent the first examples of European polyphony. Its authors would be French musicians who worked in the scriptorium of the Cathedral of Santiago, in the same way that there were sculptors, and master builders employed in the factory of the Cathedral.

Once more, this shows the high level of inter-regional integration which the Way of Santiago meant for the West and the creative cosmopolitanism of medieval Compostela.

The Xunta de Galicia (Galician Government) has agreed to promote the inclusion of the Codex Calixtinus in the register of the “Memory of the World” of UNESCO, aiming to protect the documentary and bibliographic heritage.