Trieste discovery reveals an early example of Roman military architecture

Map of the Istrian peninsula. Image: Public Domain

Map of the Istrian peninsula. Image: Public Domain

An area known as San Rocco in Muggia (northeast Italy), could hold secrets to the origins of Trieste, or Tergeste as it was once known, and provide valuable information on early Roman military architecture.

An interdisciplinary team has discovered a site with Roman military fortification systems, composed of a large central camp flanked by two minor forts. The team believes that this site, which dates back to the first decades of the 2nd century BC, is most likely where the Romans laid the first foundations of Trieste.
According to the researchers, the fortifications probably relate to the first year of the second Roman war against the Histri in 178 BC, and reported by the historian Livy.

Buried structures

LiDAR-derived digital terrain model with the location and plan of Grociana piccola, Montedoro, and San Rocco fortifications. Images: Federico Bernardini

LiDAR-derived digital terrain model with the location and plan of Grociana piccola, Montedoro, and San Rocco fortifications. Images: Federico Bernardini

The team led by International Centre for Theoretical Physics (ICTP) researchers Federico Bernardini and Claudio Tuniz, used Light Detection And Ranging (LiDAR) and Ground Penetrating Radar (GPR). LiDAR bounces laser light pulses off the ground to generate precise pictures of surface features, while GPR allows the detection of subsurface structures. Further archaeological surveys helped to assess the relative chronology of the sites.

Digital terrain models produced from the LiDAR data, revealed a plan of the ancient structures. The GPR revealed the presence of buried structures at the site, including several possible walls.

The San Rocco camp includes an area wider than 13 hectares–larger than 13 football fields–which was defended by wide ramparts and strategically located very close to the most protected natural harbour of the northern Adriatic,” says Bernardini.

Roman conquest of Istria

He adds, “The archaeological materials discovered inside and analysed in our lab date its building to the first half of the second century BC, which is when the Romans conquered Istria. This makes the camps among the earliest examples of Roman military architecture in the Roman world.

LiDAR is revolutionising archaeological studies, providing new methods for finding ancient emerging structures from prehistoric to ancient Roman times, also in areas that are totally covered by trees,” explains Tuniz. “The research team was able to unravel archaeological evidence of a crucial period of Roman history at the borders of the Roman republic.”

Details of the discovery have been published in the Proceedings of the National Academy of Sciences.