Aurelian Walls: Enclosing an Expanding Rome

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Whenever one thinks of in Rome, Italy, most will conjure up images of amazing architecture or events that took place during the Golden Age of Rome. That would be fair since basic utilities and mundane daily activities typically go without recognition.

That’s not going to be the case today as we explore some city walls while we take a closer look at the Aurelian Walls!

Interior view of the Aurelian Walls near Porta San Sebastiano.

The Aurelian Walls are a line of city walls built between AD 271 – 275 during the reign of the Roman Emperors Aurelian and Probus. The walls enclosed all the Seven Hills of Rome plus the Trastevere district.

The banks of the Tiber within the city limits appear to have been left unfortified, although they were fortified along the Campus Martius. The entire enclosed area comprised 3,500 acres and superseded the earlier Servian Wall built during the 4th Century BC under Roman King Servius Tullius.

Map of Ancient Rome with the Aurelian walls (red) and the Servian Walls (blue).

By the 3rd Century AD, the boundaries of Rome had grown far beyond the area enclosed by the old Servian Wall due to expanse of the Res Publica Romana (Roman Republic). Rome had remained unfortified during the subsequent centuries of expansion and consolidation due to lack of hostile threats against the city.

The citizens of Rome took great pride in knowing that Rome required no fortifications because of the stability brought by the Pax Romana and the protection of the Exercitus Romanus (Roman Army). However, the need for updated defences became acute during the Crisis of the Third Century, when barbarian tribes flooded through the Limes Germanicus (Germanic Frontier) and the Roman Army struggled to stop them.

3rd Century AD Roman soldiers battling Gothic troops, as depicted on a contemporary Roman sarcophagus (c. 250 AD – National Museum, Rome).

In AD 270, the barbarian Juthungi and Vandals invaded northern Italy, inflicting a severe defeat on the Romans at Placentia (modern Piacenza) before eventually being driven back. Further trouble broke out in Rome itself in the summer of AD 271, when mint workers rose in rebellion causing 1,000 deaths in the fierce fighting that resulted.

Aurelian’s construction of the walls as an emergency measure was a reaction to the barbarian invasion of 270. The historian Aurelius Victor states explicitly that the project aimed to alleviate the city’s vulnerability.

Radiate of Emperor Aurelian.

It may also have been intended to send a political signal as a statement that Aurelian trusted that the people of Rome would remain loyal, as well as serving as a public declaration of the Emperor’s firm hold on power. The construction of the walls was by far the largest building project that had taken place in Rome for many decades, and their construction was a concrete statement of the continued strength of Rome.

Roman soldiers building Hadrian’s Wall.

The construction project was unusually left to the citizens themselves to complete as Aurelian could not afford to spare a single Legionarius (Legionary) for the project. The root of this unorthodox practice was due to the imminent barbarian threat coupled with the wavering strength of the military as a whole due to being subject to years of bloody civil war, famine, and the Plague of Cyprian.

Although the walls were built in only 5 years, Aurelian himself died before the completion of the project. Progress was accelerated, and money saved, by incorporating existing buildings into the structure.

These buildings included the Amphitheatrum Castrense, the Castra Praetoria, the Pyramid of Cestius, and even a section of the Aqua Claudia aqueduct near the Porta Maggiore. As much as one sixth of the walls is estimated to have been composed of pre-existing structures.

Sentry passage near Porta Metronia.

An area behind the walls was cleared to enable it to be reinforced quickly in an emergency. To aide in the reinforcement, sentry passages were also built

The actual effectiveness of the wall is disputable, given the relatively small size of the city’s garrison. The entire combined strength of the Praetorian Guard, Cohortes Urbanae (Urban Cohorts), and Vigiles Urbani (Watchmen of the City) of Rome was only about 25,000 men (which everyone knew this was far too few men to adequately defend the City).

However, the military intention of the wall was not to withstand prolonged siege warfare since it was not common for the barbarian armies to besiege cities. Instead, the wall was a deterrent against the hit-and-run raid tactics barbarian used against ill-defended targets.

The Mausoleum of Hadrian, usually known as Castel Sant’Angelo.

Parts of the wall were doubled in height by Maxentius, who also improved the watch-towers. In AD 401 under Honorius, the walls and the gates were improved, and the Tomb of Hadrian (located across the Tiber) was incorporated as a fortress in the city defenses.

The full circuit ran for 12 miles surrounding an area of 5.3 square miles. The walls were constructed in brick-faced concrete, 11 feet thick and 26 feet high, with a square tower every 100 Roman feet (97 feet).

A latrine (circled in red) built into the wall near the Porta Salaria.

In the 4th Century AD, remodeling doubled the height of the walls to 52 feet. By 500 AD, the circuit possessed 383 towers, 7,020 crenellations, 18 main gates, 5 postern gates, 116 latrines, and 2,066 large external windows.

The Aurelian Walls continued as a significant military defense for the city of Rome until 20 September 1870, when the Bersaglieri of the Kingdom of Italy breached the wall near the Porta Pia and captured Rome. The walls also defined the boundary of the city of Rome up until the 19th Century, with the built-up area being confined within the walled area.

The Aurelian Walls remain remarkably well-preserved today, largely the result of their constant use as Rome’s primary fortification until the 19th Century. The Museo delle Mura near the Porta San Sebastiano offers information on the walls’ construction and how the defenses operated.

Section of Aurelian wall between the Porta Ardeatina and Porta San Sebastiano.

The best-preserved sections of the walls are found from the Muro Torto (Villa Borghese) to Corso d’Italia to Castro Pretorio; from Porta San Giovanni to Porta Ardeatina; from Porta Ostiense to the Tiber; and around Porta San Pancrazio.

From the northernmost location (moving clockwise), a list of gates (porte) is as follows: Porta del Popolo (Porta Flaminia) – where the Via Flaminia begins; Porta Pinciana; Porta Salaria – where the Via Salaria begins; Porta Pia – where the new Via Nomentana begins, Porta Nomentana – where the old Via Nomentana began; Porta Praetoriana – the old entrance to Castra Praetoria, the camp of the Praetorian Guard; Porta Tiburtina – where the Via Tiburtina begins; Porta 

Section of wall near the Pyramid of Cestius.

Maggiore (Porta Praenestina) – here 3 aqueducts meet and the Via Praenestina begins; Porta San Giovanni – near the Basilica di San Giovanni in Laterano; Porta Asinaria – where the old Via Tuscolana began; Porta Metronia; Porta Latina – where the Via Latina begins; Porta San Sebastiano (Porta Appia) – where the Appian Way begins; Porta Ardeatina; Porta San Paolo (Porta Ostiense) – next to the Pyramid of Cestius, leading to Basilica di San Paolo fuori le Mura, where the Via Ostiense begins.

From the southernmost location (moving clockwise), a list of gates in Trastevere is as follows: Porta Portuensis; Porta Aurelia Pancraziana; Porta Settimiana; and the Porta Aurelia-Sancti Petri.

We hope you enjoyed today’s wall climbing experience. Be sure to check us out for updates on Facebook and Twitter.

Till next time, Don’t Stop Rome-ing!



Aldrete, Gregory S. Daily Life In The Roman City: Rome, Pompeii, And Ostia, Greenwood Press, 2004. ISBN 0-313-33174-X.

Claridge, Amanda. Rome: An Oxford Archaeological Guide. Oxford University Press, 1998. ISBN 0-19-288003-9.

Southern, Pat. The Roman Empire from Severus to Constantine, Routledge, 2001. ISBN 0-415-23943-5.

Aurelius Victor. De Caesaribus.

Mancini, Rossana. The Aurelian Walls of Rome: Atlas of a Masonry Schedule. Quasar, Rome, 2001. ISBN 88-7140-199-9.

Museum of the Walls official website

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