Aurelian Walls

The Aurelian Walls form a mighty circuit of brick-faced concrete that still circles central Rome. Built between AD 271 and 275 under Emperor Aurelian, they enclosed the seven hills, the Campus Martius and Trastevere on the Tiber’s right bank. The full circuit stretched for 19 km and enclosed 13.7 km², cutting through densely populated areas that already reached 2.8 km from the Forum’s Golden Milestone. The walls were originally 3.5 m thick and 8 m high, with a square tower every 29.6 m. By AD 500 the defences had grown to 16 m high, 383 towers, 7,020 crenellations and 18 main gates.

Their construction was an emergency response to invasions during the third-century crisis. After Juthungi and Vandals raided northern Italy in AD 270, mint workers in Rome rose in rebellion the following summer. Aurelian ordered the walls built in five years, using existing buildings such as the Amphitheatrum Castrense and the Pyramid of Cestius. The historian Aurelius Victor records that the project aimed to show the emperor’s firm hold on power and to reassure citizens during uncertain times. Despite a garrison of only 25,000 men, the walls deterred hit-and-run raids rather than prolonged sieges.

Today the best-preserved sections run from Muro Torto to Castro Pretorio and from Porta San Giovanni to the Tiber. The Museo delle Mura near Porta San Sebastiano explains how the defences worked. Visitors can walk the walls at Porta San Pancrazio, where Maxentius doubled the height in the early fourth century. Gates such as Porta Maggiore and Porta San Paolo still mark the start of major roads like the Appian Way. The walls remained Rome’s main fortification until 1870, when Italian troops breached them at Porta Pia.