In the early 1440s, the west facade of Burgos Cathedral consisted of the three lower storeys and, at the least, part of today’s fabric of the fourth storey of the south tower. The cathedral had had this form since the last third of the thirteenth century, when the project of the facade construction had been abandoned. The bishop of Burgos, don Alonso de Cartagena (1435-1456), initiated the continuation of its construction in 1442 with the support of the cathedral chapter and civil authorities. Juan de Colonia (†1481) was the master builder who finished the construction of the facade in 1458 with the elevation of two openwork spires. The design of the Burgos spires consists of motifs and ideas that come from several tower projects of the southwest territories of the Empire. Nevertheless, the design of the Burgos spires is singular compared with coeval spire projects. The construction of the spires was integrated into the design of a project the purpose of which was to complete a work of architecture that h...