Pro restauratione murorum huius excellentissime urbis. Le Mura Aureliane di Roma nel Basso Medioevo

The Aurelian Walls of Rome had extensive late medieval renovations. The constant characteristics of these restorations are the irregular arrangement of the stones of the outer layers ('flint', tuff, peperino, travertine, fragments of marble and brick) and the frequent presence of partial horizontal rows of brick. The mortars are lime and sand, almost all without pozzolana. This type of masonry is not rare in the Roman area, mainly in fortified buildings, dating back to the same centuries. The masonry technique as a whole (core and external layers) seems an explicit quote from ancient architecture, perhaps not cultured but spontaneous, also born from the availability of reused material, roughly reworked, taken from the ancient Roman nuclei in opus caementicium, after the depletion of more easily removable stones. The observation of the holes for scaffolding shows the persistence of some characteristics of the early medieval construction processes.