Dozens of new Roman army camps dating back two millennia have been discovered in northern Spain.
Experts used remote sensing technology to discover the 66 camps of various sizes that the Romans allegedly used for training and shelter during one of their most infamous conflicts – the conquest of Spain.
Researchers can identify the initial location of the camps by signs of culture, depressions and weak physical traces in the country that appear in satellite images.
The 66 camps were probably active towards the end of the 200-year battle for the Iberian Peninsula – the land mass formed by Spain and Portugal – which the Romans knew as “Hispania”.
The analysis of the 66 camps, close to the Cantabrian Mountains in northern Spain, shows that the Roman army had a greater presence in the region than previously thought in the last stages of the bloody battle.
The Roman occupation gradually increased from the south of the peninsula to the north over two centuries – from about 220 BC. until 19 AD.
Roman military presence in northern Castile. The first 25 sites included in this new study are colored in red
Roman military presence in Leon. The image shows the location of the other sites in red, numbered from 26 to 66.
“We identified so many sites because we used different types of remote sensing,” said the study’s author, Dr. João Fonte, of the University of Exeter.
“Laser scanning in the air gave good results for some sites in more distant places, because it showed very good earthworks.
“Aerial photography worked better in plain areas to detect landmarks.
“The remains belong to the temporary camps that the Roman army set up when they moved on hostile territory or when they performed maneuvers around their permanent bases.
“They reveal the intense Roman activity at the entrance to the Cantabrian Mountains in the last phase of the Roman conquest of Hispania.”
The color-coded image shows the progress of the Roman conquest of the Iberian Peninsula (known as Hispania by the Romans), starting with 220 BC. The conflict ended in 19 BC, when Augustus, the first Roman emperor, annexed the entire peninsula to the Roman Empire.
The new sites are located at the foot of the 180-mile-long Cantabrian mountain range, which stretches from west to east along the tip of Spain.
The conflict between the Romans and the natives was concentrated in the Cantabrian Mountains at the end of the 1st century BC.
This suggests that soldiers crossed low and high areas, using ridges in the mountains to stay out of place and provide more protection.
The fact that there were so many armed camps in the region shows the “huge logistical support” that allowed the soldiers to conquer the area.
Roman soldiers allegedly attacked indigenous groups from different directions, the team said.
The camps were used to help move to distant places and to help soldiers stay in the area during the cold winter months.
Some camps could have housed soldiers for weeks or months, and others overnight.
The purpose of their occupation was to expand the empire and be able to exploit natural resources such as tin and gold.
Roman military sites in the northwest of the Iberian Peninsula depending on the date of their discovery or publication. The main administrative units mentioned in this paper are Galicia (GAL), Asturias (AST), Castilla y León (CyL), Cantabria (CAN) and northern Portugal (POR).
Only a handful of Roman military sites were known in northwestern Iberia until the late 1980s, experts say.
But since the turn of the century, a “digital revolution” and the potential of remote sensing techniques have fueled the discovery of new camps.
In the last five years, the remains of the camps have been reported in milder topographies in central and western Galicia, as well as in northern Portugal.
Their camps and temporary occupations usually left fragile and subtle traces on the surface.
The ditches or earth and stone walls that protect these fortifications have been filled and flattened.
But a combination of different remote sensing images and fieldwork shows the perimeter shape of military camps, often a rectangle like a playing card.
For this study, the experts analyzed aerial photos and satellite images, created 3D terrain models from LiDAR data, and used drones to create detailed site maps.
This included resources from the Spanish National Geographic Institute (IGN) and geoportals such as Google Earth or Bing Maps.
The precise location allowed the archaeological field projects to take place later, providing new information about the Roman camps in this region.
Archaeological features of northern Castile-southern Cantabria, as seen in satellite images provided by Google Earth
Aerial photos of Tortolondro Camp (black) (A), Roman Road (white) and Quintanilla de Riofresno Camp (black)
The research will continue so that experts can examine the relations established by the Romans with the 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 using drones, in order to gain a better understanding of their structures or the evolution of their state of conservation.
Work continues in the northern city of Burgos and the nearby town of Sasamón, including a study of the settlement of Cerro de Castarreño and its conquest in the 1st century BC.
The findings were shared with cultural and heritage organizations so that they can be protected in the future.
The research was published in the journal Geosciences.