Astronomical knowledge in sacred medieval Italian architecture

This text describes the results of archaeoastronomical examinations of sacred buildings in Italy dating from the medieval period. The buildings are complex and well-constructed, and were mainly built in the period after the year 1000 by workmen who were both expert and cultured. The training of the architects and of the possible archaeological knowledge which would have been widespread at the time, will also be briefly dealt with. The buildings can be subdivided according to type: abbeys, cathedrals, basilicas, and baptisteries. An in-depth historical analysis has been carried out for each site: these are buildings which have undergone numerous changes though the centuries due to war, damage or because of changes in architectonic language or in the building’s functions. The various surveying methods used will be described (direct, instrumental analysis, scanner laser 3D), as well as the orientations (instrumental survey). The issues considered include: the importance of the astronomical orientation of the buildings, the design relationships between the floor plans of the buildings and their elevations (the arrangement of the windows), the lighting effects created to illuminate liturgical areas and decorative displays, and the presence of astronomical and astrological iconography.