Aurelian Walls

The construction of the Aurelian Walls was decided by the emperor Aurelian in AD 270, to meet the defensive needs dictated by the threat of invasion by Germanic peoples, later known as the barbarian invasions. At the time, the Roman empire was experiencing a period of severe crisis, making it more difficult to control the peoples pressing against the borders of the empire. From the middle decades of the third century onwards, the Goths began to move southwards from their homelands in Scandinavia, spreading throughout central and southern Europe and sacking numerous cities in their path. City walls had already saved cities like Milan and Verona, leading the emperor Aurelian to build massive defensive walls to protect the city of Rome in the same way. The city had lacked defences since the early imperial period, when the Servian walls had almost completely disappeared, concealed beneath the city that had spread far beyond its primitive wall circuit.

Awareness of the impending crisis – in AD 270 the advance of the Goths and Alemanni on Piacenza had been halted with difficulty, demonstrating that even the capital of the empire was under serious threat – led to work being completed in record time, probably making use of military experts to design the walls. To speed up construction work, pre-existing structures were used wherever possible: for example, on the eastern boundary of the Esquiline hill the walls incorporated the arches of the aqueducts crossing the Via Labicana and Via Prenestina at what is now Porta Maggiore. The same was true at Porta Tiburtina, where the conduits of the Aqua Marcia, Aqua Tepula and Aqua Iulia crossed the Via Tiburtina. In the stretch now behind Termini Station, the aqueducts e were completely incorporated into the walls, built entirely of bricks and equipped on the top with a walkway for the soldiers on guard duty. Completed in AD 275, this defensive wall circuit protected Rome for nearly 150 years, until the western emperor Honorius was faced with a resurgence of attacks by barbarian peoples. In the early fifth century, the walls were therefore completely renovated; their height was significantly increased and the gates, including the Porta Tiburtina and Porta Maggiore, were reinforced with defensive bastions. In fact, we do not know if the walls would have withstood attack by the Goths of Alaric: according to the sources, they entered Rome in 410 without encountering resistance, because the Porta Salaria had for some inconceivable reason been left open. Over the following centuries the walls withstood attacks by the Ostrogoths during the reign of Justinian and, shortly after, the long siege of the Lombards.

Their last complete renovation was undertaken by Pope Pius IV, who reinforced the walls in the sixteenth century fearing attacks by the Saracen pirates who were devastating the coasts of Lazio at the time. On the same occasion he also reinforced the wall circuit protecting the Vatican, built by Pope Leo IV in the mid-ninth century. The walls still played a crucial role in the nineteenth century, when the end of the temporal power of the popes was marked by the opening of the famous Breach of Porta Pia, on 20 September 1870.