Modern archaeology reveals the secrets of an Iron Age power center

New excavations in Uppåkra are at the forefront of state-of-the-art archaeological techniques. By combining big data, data modeling and DNA sequencing, researchers are currently solving important parts of a historical puzzle. Perhaps we will find out if the Justinian Plague, the precursor of the Black Death, has reached Uppåkra. Until now, this was uncertain.

Torbjörn Ahlström, Professor of Historical Osteology at Lund University, stands on a hill outside Lund. His gaze falls on the fertile soil that has served the people of the area for centuries.

Torbjörn Ahlström is about to start a new project in Uppåkra. Today it is a quiet village in rural southern Sweden, but earlier in history it was the most powerful center of the Scandinavian countries for over 1000 years (between 100 BC and the 10th century).

Uppåkra is classified as the largest Iron Age settlement in the Scandinavian countries, and one of the richest sites in Northern Europe for archaeological finds. So far, the excavations have been periodic and have covered only a fraction of the area.

“The autumn of 2022 is special, however. We will now unveil Hallen, a 30-meter-long building in the heart of the community, the epicenter of power in Uppåkra,” explains Torbjörn Ahlström.

Supported by new technologies

The archaeological team working on Hallen is an experienced group: “regular” archaeologists; an archaeologist in charge of stratigraphy (documentation of the different cultural layers); an animal osteologist (analyzing animal bones); as well as a paleobotanist (who studies fossilized plants) will all work on the excavations using the updated toolbox of modern archaeological techniques.

“Archaeology is in the midst of its third scientific revolution and offers us entirely new opportunities,” says Torbjörn Ahlström.

Simply put, the team combines several techniques to paint a broad picture of life in the great center of power of the Scandinavian countries.

“For example, we use DNA sequencing in combination with isotopic analyzes of strontium, oxygen, carbon and nitrogen. This has actually revolutionized archeology and is giving us answers about kinship, mobility, habits and health in ancient cultures,” says Sandra Fritz . , Project Assistant in Historical Osteology at Lund University.

By sequencing prehistoric DNA, various findings can be identified and compared with global databases.

“We extract soil DNA from cultivated soil, a method that is completely new, which basically means that we take a soil sample and extract all the DNA available,” says Torbjörn Ahlström.

Specifically, a tube is pushed into the earth and sent to a lab for DNA analysis. This technique differs from other types of DNA analysis that are based on bone remains, from animals or humans, and not from soil.

Credit: University of Lund

“Combined with other methods such as micromorphology, archaeogenetics and isotope and radiographic analyses, it gives us a good chance to get a fairly detailed picture of the prehistoric conditions in Uppåkra,” says Sandra Fritz.

“Personally, I hope to find the answer to the question of whether Uppåkra was reached by the Justinianic Plague, the precursor of the Black Death, which broke through here in several waves between 1300 and 1700. We know that Germany and England in the 6th century, but in Scandinavia it hasn’t been localized yet,” says Torbjörn Ahlström.

Found Uppåkra by accident

Uppåkra was discovered more or less by accident. In 1934, the foundations of a pigsty were to be excavated in the village of Uppåkra, close to the church.

“The soil revealed the first signs of community in Uppåkra. Today we have 28,000 artifacts; pottery, charred bones and charcoal – in short, a huge prehistoric site,” says Torbjörn Ahlström.

The entire Uppåkra site is large, a whopping 50 hectares, and the excavations are time-consuming. So far, researchers in Uppåkra have found, among other things, a brewery, jewelry and a glass bowl most likely made on the shores of the Black Sea.

“What was its relationship with the continental Roman Empire? Did the people of Uppåkra fight for it as auxiliaries?” says Torbjörn Ahlström.

He points to the other side of the valley and walks past the indicated spot of the hall. Four wooden posts are driven into the ground to mark another central location, Kulthuset.

“Religious rituals took place here, close to the Hallen power center,” says Torbjörn Ahlström.

He describes how Hallen went through at least seven different construction phases and concludes that the placement of Hallen and Kulthuset was important to people – they were always rebuilt in the same place.

“We hope to discover many finds that can tell us something about the use of power during this time. The history of what actually happened in Uppåkra’s Hallen is an indication of what happened during much of the Iron Age,” says Torbjorn Ahlstrom.

How the new methods work

87/86Sr (analysis of strontium isotopes) and 18/160 (analysis of oxygen isotopes): Strontium and oxygen isotopes accumulate in rock and rainwater. From here they pass to the vegetation and nearby watercourses. Their signatures vary between areas and are specific to the original sites. By means of food and drink, humans and animals adopt the isotopic signatures of their specific areas.
15N (nitrogen isotope analysis) and 13/12C (stable carbon isotope analysis): Nitrogen and carbon isotopes indicate the type of food consumed.
Ancient DNA (aDNA): Like most organic material, DNA has undergone evolutionary processes. By sequencing prehistoric DNA, parts of genomes can be identified and matched with global databases. This is useful not only for the search for relationships, mobility and human and animal species, but also for the identification of bacteria (eg tuberculosis).
Micromorphology: extraction of vertical soil horizons allows detection of individual forms of activity at a site. Thin layers resulting from events can be identified under a microscope.
Georadar: Ground penetrating radar (georadar) measures differences in composition and density. It can be used to detect events. Such investigations can make it easier to identify construction and/or digging patterns. These can lead archaeologists to sites of antiquarian interest.