The monumental complex of the Walls of Santo Stefano constitute one of the most important historical remains of the Roman period (2nd C. A.D.) in the territory of the Anguillara Sabazia Municipality. Although there is controversy about the actual period of construction, many scholars date the structure back to the 2nd C. A.D., coinciding with the refurbishment of the ancient via Clodia, along which it lay.
The Walls of Santo Stefano are a typical example of rustic villa of the Roman Age, complete with wonderful marble decorations and all the necessary practical elements required for a country mansion.
In the immediate vicinity there were, after all, agricultural produce storage depots and a water cistern.
The building, with its three floors, each of which had arched windows, reached the height of 18 metres and must have been part of a much larger complex. In Medieval times, the villa was transformed into a church dedicated to the cult of Saint Stephen.
The church was built during the time when the ruins of the Roman Villa were refurbished to become a convent building (11th C.). Its current name is based on this usage. The remains of the sacred structure are important because they are unusual for a landfill of the 11th C.: usually the brick work was somewhat irregular, while the opus vittatum (tufa blocks intersected with brick bands) found in S. Stefano is fairly regular.
Consequently the apse is similar only to the structures of the church of S. Pietro at Albano and S. Passera in the Roman suburbs.
The exceptional architectural quality of the ruins is proven by the fact that already in the 15th C. they were studied by eminent architects such as Andrea Palladio, the designer of many magnificent Veneto villas including “La Rotonda” and Pirro Ligorio, the architect who succeeded Michelangelo in overseeing the construction of Saint Peter’s.