L'ingresso delle ferrovie pontificie attraverso le mura Aureliane: dibattito e progetti nell'ambito della pianificazione militare della Roma di Pio IX The Papal Railways' entry through the Aurelian Walls: debate and projects in the context of Rome's military planning under Pius IX

This paper highlights the transformations undergone by the Aurelian Walls following the introduction of the papal railways into the city of Rome during the reign of Pius IX. The paper examines the debate and studies carried out in planning the railways' entry into Rome, beginning with the various projects for the placement of railway stations in various areas of the city—at Prati di Castello, Villa Borghese, the Colosseum, and San Giovanni in Laterano—followed by the initial temporary solutions that envisioned stations outside the walls for military security reasons (outside Porta Portese for the Rome-Civitavecchia line and outside Porta Maggiore for the Rome-Ceprano line)—up to the final decision to locate the central railway station in the Termini area, characterized by clear urban expansion decisions and specific military defense dynamics. Previous studies on Rome's military defenses during the pontificate of Pius IX (MANFREDI 2022; MANFREDI 2024) have highlighted the strategic aspects that guided railway planning from the beginning. The question of whether or not the railway should enter the city walls was characterized by a succession of proposals originating, largely, from the two companies granted concessions for the construction of the papal railways (Pio Latina and Pio Centrale, both merged into Pio Centrale in 1860). These companies were entrusted with the study of the positioning of the stations, with decisive input from the French government and Ministry of War. Surrounding these proposals, a series of projects, including private initiatives, envisioned major urban transformations near the walls, surrounding the construction of the stations themselves. The underlying theme of the story remains the debate over whether or not to open passages for the railway within the city walls. This had long been planned at Porta Maggiore, where the Rome-Ceprano line terminated, for the construction of the Colosseum station. The final location of the central railway station at Termini, in an urban area well defended by old and new barracks, not far from the walls and a stone's throw from the seats of power (the Quirinale and the Ministry of Arms at the Pilotta), eventually led to the opening of the so-called Three Arches north of Porta Maggiore. Their construction history has been reconstructed up until the gradual demolitions that took place between the second and third decades of the 20th century, for the passage of an ever-increasing number of tracks.