The eleven diligent volumes of Don Antonio López Ferreiro's Historia de la Santa Apostolica Metropolitana Iglesia de Santiago de Compostela contain a mass of documents related to the history of the cathedral of Santiago, but, in spite of this wealth of material, the date when the building was begun has never been clearly established. The Historia Compostelana (i, 78) states: ‘Est autem B. Jacobi specialis et praeclara nova Ecclesia incoepta Era I.C.XVI. V Idus Jul.’ (an. 1078), thus giving the date as A.D. 1078. However, in the Codex Calixtinus, a twelfth-century piece of pilgrimage propaganda, containing among other things a description of the cathedral, no less than four different dates are given for the event: ‘Ecclesia autem fuit incepta in Era MCXVI. Ab anno vero quo incepta fuit usque ad letum Adefonsi fortissimi et famosi regis Aragonensis habentur anni LIX, et ad necem Henrici regis Anglorum LXII, et ad mortem Ludovici pinguissimi regis Francorum LXIII, et ab anno quo primus lapis in fundamento eius ponitur usque ad illum quo ultimus mittitur XLIIII anni habentur.’