This article comprises four parts: 1) Codicological study of a book written on parchment, which contains a copy of the royal charters granted to the city of Murcia. I have examined the composition of the cuadernos, the layout of the text and the decoration; I have traced the history of the manuscript, and discovered the name of the scribe and the date: 1506. 2) Assessment of the documents in the book, all of which are letters from the Kings of Castile, ranging from Alfonso X to the Catholic Kings, Fernando and Isabel, and contain legal and economic charters granted to the city of Murcia. 3) Study of the second part of the book, which was written on paper at different times during the 16th and 17th centuries. 4) Appendix with the summaries (regestas) of the 143 manuscripts included in the book and which date from 1266 to 1621.