A new study suggests the Roman siege of Pompeii may have involved an ancient repeating weapon, a kind of early “machine gun” linked to Rhodes, based on unusual marks still visible on the city’s northern walls.
The study, published in Heritage, argues that clusters of small, square-shaped impact marks at Pompeii match ancient descriptions of the “polybolos,” a repeating dart-thrower described by Philo of Byzantium in the 3rd century B.C. Lead author Adriana Rossi of the University of Campania Luigi Vanvitelli said the pattern of the damage offers new support for that idea.
The marks lie between the Vesuvio and Ercolano gates, an exposed stretch of Pompeii’s defenses that Roman forces under Lucius Cornelius Sulla attacked during the siege of 89 B.C.
Researchers said the area’s history makes the traces especially important. The wall section was buried by the eruption of Mount Vesuvius in A.D. 79, helping preserve damage that may date to the Republican-era assault.
Pompeii attack marks an ancient Greek “machine gun” from Rhodes
Earlier studies focused mainly on larger, round impact marks caused by stone projectiles. Rossi and her team turned to a different set of traces. These are smaller cavities with a more angular shape. In several cases, they appear in fan-like groups, spaced closely along a curved line.
That pattern stands out, the study said, because it does not match damage from stone balls or sling bullets. Instead, researchers compared it with Philo’s account of the polybolos, a weapon that fired darts in rapid sequence.
In his description, the shots did not spread widely. They fell close together along a narrow curved path aimed at a single target.
Researchers used high-resolution digital tools to examine the marks, including 3D survey methods, photogrammetry and reverse modeling.
The goal was to measure the cavities in detail and test what kind of projectile could have made them. The team said the size, shape and spacing of the marks are consistent with metal-tipped darts rather than round stone ammunition.
Fan-shaped wall strikes strengthen the dart-thrower theory
The study does not claim final proof. No physical remains of the weapon were found at Pompeii, and no arrowheads have been recovered from the wall. Researchers said centuries of weathering, repairs and volcanic deposits have altered the original surface. Even so, they argue the evidence is strong enough to support the polybolos as a working hypothesis.
The Rhodian link adds historical context. Philo attributed the weapon to Dionysius of Alexandria, who built it in Rhodes, a center known in antiquity for military engineering and artillery expertise. The study said that the connection makes the Pompeii scenario more plausible, especially given the wider military contacts of the period.
Rossi’s team said the findings could reshape how scholars view the siege of Pompeii. Rather than relying only on standard artillery, Roman forces may have used a more advanced repeating weapon to target defenders moving along the walls.
