Taking the High Ground: Ancient Roman Camp Used to Reach Northwest Iberia Found

Gallaecia, also known as Hispania Gallaecia, was an ancient Roman province in what is now Northwest Iberia — and modern technology has helped uncover a long-lost camp built and used by Roman soldiers to take the region.

The discovery of the ancient Roman camp marks the largest and oldest Roman fortification excavated so far in the regions of present-day Galicia and northern Portugal. Researchers behind the discovery of the ancient Roman camp include Dr. João Fonte from the University of Exeter, who also released the first report on the find on Thursday, June 24.

A Camp Used in Ancient Roman Campaigns

Experts date the foundations of the enclosure walls to be from around 200 BC. The age was approximated after the team analyzed a part of the sediment collected from the wall foundations, using a method called optically stimulated luminescence (OSL) dating technique. According to a Utah State University webpage, the OSL dating method is used to estimate the age of an object depending on the last time quartz sediments were last exposed to sunlight. Since quartz sediments — small grains of the material — could be transported by air, wind, water, or ice, it is often exposed to sunlight which zeroes and previous luminescence signals. Once it is buried though, it is kept from sunlight exposure and starts absorbing natural radiation, which offers clues as to its age.

In the latest discovery, the campsite of Lomba do Mouro, located in Melgaço, Portugal, is the oldest among scientifically identified Roman camps so far in the Galicia and northern Portugal regions. Furthermore, the construction of the fortification might actually be connected to the earliest Roman military campaigns toward what would be the Roman province of Gallaecia. It was believed to be created by some 10,000 Roman soldiers while crossing the Laboreiro Mountain situated between the rivers of Minho and Lima.

Experts additionally believe that the Lomba do Mouro camp was intended to be a temporary fortification as the Roman armies advanced, built rather quickly, and was supposed to be used for only a day or weeks at most during the warmer months. To avail of the natural terrain's strategic advantage, the Roman soldiers crossed through the high ground of the Laboreiro Mountain. The Gallaecia campaign was well documented in written history, with both fighting and amicable solutions reached with the local communities at the time.

The Challenges of Tracking These Temporary Fortifications

Temporary camps like the one on Lomba do Mouro are exceptionally hard to find using conventional methods because of how little archaeological evidence survives. These structures are not meant to be used for extended periods of time and most of the time, the ancient Roman soldiers who erected them also destroyed them on purpose when they were no longer needed.

"Written sources mention the army crossing different valleys, but until now we didn't know exactly where," Dr. Fonte explained in the Exeter release. "Because of the temporary nature of the site, it's almost impossible to find without using remote sensing techniques, and radiocarbon dating wouldn't have been accurate because plant roots creep into the structure."