The Churches of Santiago de Compostela, a diachronic analysis of their orientations

The orientation of nearly 50 churches in the historic city of Santiago de Compostela are presented. These include churches built along the history of the town, from the early Medieval period until the end of the 20thcentury. Interestingly, all churches built before the Council of Trent appear to have orientations consistent with canonical prescriptions, notably in two flavors. One would be consistent with the canonical equinox at the date of construction, possibly dictated by the orientation of the Cathedral itself. The other orientation is set a few degrees south of due east and could be dictated by the streets of the Medieval town. After the Council of Trent churches were built mostly to have the façade perpendicular to a main street, so that the apse and the altar no longer are systematically facing towards the rising sun.