The masons' marks in the western part of the cathedral of Santiago de Compostela: an approach to its construction history

In order to relate a building to its historical context, the examination of the masons' marks, together with the stylistic analysis of the sculpture, the archaeological reading of the masonry and the documentary evidence can be an essential link to understand its relative chronology. The archaeological investigation in the western parts of the cathedral of Santiago de Compostela in northern Spain shows to what extent the documentation of the masons' marks can help to understand the cathedral and its construction history. Distinct masons' marks relate the west crypt of the cathedral to the narthex and the gallery. In addition to visible structural changes in the masonry they provide secondary evidence for the different phases of construction. As the analysis of the fabric and the masons' marks underline, the genesis of the Portico de la Gloria is the result of a structural intervention led by Master Mateo at the end of the 12th century, which changed the west end including the crypt.