A passage in the Norse Sverris Saga, the 800-year-old story of King Sverre Sigurdsson, describes a military raid that occurred in AD 1197, during which a body was thrown into a well at Sverresborg Castle, outside Trondheim in central Norway, likely as an attempt to poison the main water source for the local inhabitants. A new study published in the Cell Press journal iScience on October 25 describes how researchers used ancient DNA to corroborate the events of the saga and discover details about the "Well-man," blending history and archaeology with science and setting a precedent for future research on historical figures.
"This is the first time that a person described in these historical texts has actually been found," says Professor Michael D. Martin of the Norwegian University of Science and Technology's University Museum in Trondheim, Norway. "There are a lot of these medieval and ancient remains all around Europe, and they're increasingly being studied using genomic methods."
In 1938, bones were found in the well at Sverresborg Castle, but researchers at the time lacked the tools to do much aside from visual analysis. Now, radiocarbon dating and advanced gene-sequencing technology have allowed researchers to craft a more intricate picture of who the Well-man was. Radiocarbon dating confirmed that the body is approximately 900 years old, and studies conducted in 2014 and 2016 confirmed that the body belonged to a male who was between 30 and 40 years old at the time of death.
"The text is not absolutely correct—what we have seen is that the reality is much more complex than the text," says archaeologist Anna Petersén of the Norwegian Institute of Cultural Heritage Research in Oslo, Norway.
"We can corroborate what actually happened in a more neutral way," says Dr. Martin Rene Ellegaard of the Norwegian University of Science and Technology. As part of his work toward a doctoral degree, Ellegaard used samples of a tooth obtained from the Well-man's skeleton to sequence his genome. Using this information, the team was able to ascertain that he most likely had blue eyes and blond or light-brown hair, and his ancestors likely hailed from the southernmost Norwegian county of present-day Vest-Agder.
The researchers were able to draw conclusions about the Well-man's ancestry thanks to a large amount of reference data from the genomes of modern-day Norwegians made available through a collaboration with Professor Agnar Helgason at deCODE Genetics in Iceland. "Most of the work that we do is reliant on having reference data," says Ellegaard. "So the more ancient genomes that we sequence and the more modern individuals that we sequence, the better the analysis will be in the future."
"Those reference data are literally thousands of genomes of modern Norwegians and many thousands of other European genomes," says Martin.
However, this technology has its limitations, as sampling the Well-man's genome required removing the outer surface from his tooth—to avoid contamination from those who had handled it in non-sterile environments, such as during excavation—and grinding the tooth into a powder. This means that the sample can no longer be used for further tests, and researchers were not able to get data on any pathogens the Well-man may have been carrying at his time of death.
"It was a compromise between removing surface contamination of the people who have touched the tooth and then removing some of the possible pathogens … there are lots of ethical considerations," says Ellegaard. "We need to consider what kind of tests we're doing now because it will limit what we can do in the future."
The researchers say that they would like to test samples from other historical figures. "The important Norwegian Saint Olaf is thought to be buried somewhere in Trondheim Cathedral," says Martin, "so I think that if eventually his remains are uncovered, there could be some effort to describe him physically and trace his ancestry using genetic sequencing."
Speaking to this new technique of blending of history and science, Petersén concludes, "It's a fantastic result on what Ellegaard and Martin's method can bring to archaeology in such a strange or rare context like this is."
