Dozens of new Roman army camps dating back to two millennia have been discovered in northern Spain.
Experts used remote sensing technology to uncover the 66 camps of various sizes that the Romans are said to have used for training and shelter during one of their most notorious conflicts – the conquest of Hispania.
Researchers can identify the original location of the camps through cropmarks, depressions and faint physical traces in the land that appear on satellite images.
The 66 camps were probably active towards the end of the 200-year battle for the Iberian Peninsula – the landmass of Spain and Portugal – known by the Romans as “Hispania”.
Analysis of the 66 camps, located close to the Cantabrian mountains in northern Spain, shows that the Roman army had a greater presence in the region than previously thought during the final stages of the bloody battle.
Roman occupation gradually shifted from the south of the peninsula to the north over the course of two centuries – from about 220 BC to 19 AD.
Roman military presence in the north of Castile. The first 25 sites included in this new study are colored red
Roman military presence in Leon. Image shows location of other sites in red, numbered 26 to 66.
“We’ve identified so many sites because we’ve used different types of remote sensing,” said study author Dr. João Fonte of the University of Exeter.
Airborne laser scanning gave good results for some sites in more remote places because the groundwork showed very well.
‘Aerial photography worked better in lowlands for detecting crop marks.
The remains are of the temporary camps that the Roman army set up when moving through hostile territory or conducting maneuvers around their permanent bases.
“They reveal the intense Roman activity at the entrance to the Cantabrian Mountains during the final phase of the Roman conquest of Hispania.”
Color-coded image shows the progress of the Roman conquest of the Iberian Peninsula (known as Hispania by the Romans), starting in 220 BC. The conflict ended in 19 BC when Augustus, the first Roman Emperor, annexed the entire peninsula into the Roman Empire
The new locations are at the base of the 180-mile Cantabrian mountain range, which stretches from west to east along the summit of Spain.
The conflict between Romans and natives centered on the Cantabrian Mountains at the end of the 1st century BC.
This suggests that soldiers crossed between lowlands and highlands, using ridges in the mountains to stay out of the site and give themselves more protection.
The fact that there were so many army camps in the region proves the ‘immense logistical support’ that allowed soldiers to conquer the area.
Roman soldiers are said to have attacked native groups from different directions, the team said.
Camps were used to support relocations to remote locations and to help soldiers stay in the area during the cold winter months.
Some camps may have housed soldiers for weeks or months, others overnight.
The purpose of their occupation was to expand the empire and exploit natural resources such as tin and gold.
Roman military sites in the northwest of the Iberian Peninsula based on their discovery or date of publication. The main administrative units mentioned in this document are Galicia (GAL), Asturias (AST), Castile and León (CyL), Cantabria (CAN) and Northern Portugal (POR)
In the late 1980s, only a handful of Roman military sites were known in northwestern Iberia, experts say.
But since the turn of this century, a ‘digital revolution’ and the potential of remote sensing techniques have fueled the discovery of new camps.
Over the past five years, the remains of camps have been reported in the softer topographies of central and western Galicia, as well as northern Portugal.
The camps and their temporary occupations usually left fragile and subtle traces on the surface.
The ditches or the earth and stone walls that protect these fortifications have been filled in and flattened.
But a combination of different remote sensing images and fieldwork shows the outline shape of the military camps, often a rectangle like a playing card.
For this study, experts analyzed aerial photography and satellite images, created 3D models of the terrain based on LiDAR data, and used drones to create detailed maps of the locations.
This included sources from Spain’s National Geographic Institute (IGN) and geo portals such as Google Earth or Bing Maps.
Identifying sites allowed archaeological fieldwork projects to take place, which provided new information about Roman camps in this region.
Archaeological features of northern Castile and southern Cantabria, as seen on Google Earth satellite images
Aerial photographs of the camp at Tortolondro (black) (A), the Roman road (white) and the camp (black) at Quintanilla de Riofresno
The research will continue so that experts can explore the relationships the Romans have built with indigenous communities called Vaccaei, Turmogi, Cantabri, Astures and Callaeci, according to Greek and Latin sources.
The team is currently developing a project to catalog and document all Roman camps in the province of León by means of drones in order to gain a better understanding of their structures or the evolution of their conservation status.
Work is also underway on the northern city of Burgos and the nearby city of Sasamón, including a study of the Cerro de Castarreño settlement and its conquest in the 1st century BC.
The findings have been shared with cultural and heritage organizations so that they can be protected in the future.
The research is published in the journal Geosciences.