In 1197, an ancient saga records that a body was flung into a well by the besiegers of Sverresborg castle outside Nidaros, now the central Norwegian city of Trondheim. More than 800 years later, scientists think they may have found him.

“While we cannot prove that the remains are those of the individual mentioned in the saga, the circumstantial evidence is consistent with this conclusion,” the researchers said in a study published in the journal iScience.

“I would say there’s a high probability this is the man from the saga – not only based on the dates, but also as the whole context matches what’s written,” the archaeologist Anna Petersén, who led the excavation work, told the public broadcaster NRK.

The Sverris saga relates the life of the ambitious Norwegian king Sverre Sigurdsson, who rose to power in the late 12th century during a period of political instability and civil war that continued for decades after his death in 1202.

The 182-verse saga, believed to have been written at the time of the events it relates to – and partly under the king’s supervision – by an Icelandic abbot who was close to Sverre, is described as unique in the rich accounts it gives of his many battles.

One passage describes in vivid detail how in 1197 the king’s Roman Catholic enemies attacked his stronghold at Sverresborg, pillaging the castle and razing every dwelling inside while the monarch was away in Bergen.

The besieging forces, known as Baglers from the Norse word for “bishop’s wand”, entered the castle through a secret door while its defenders, known as Birkebeiner or “birch legs”, supposedly because they wore birch bark on their legs, were eating.

The Baglers “took all the goods that were in the castle, and then they burned every single house that was there,” the Sverris saga reads. “They took a dead man, and cast him headfirst into the well. Then they piled stones into it until it was full.”

The ruins of Sverre Sigurdsson’s castle near the modern-day city of Trondheim in central Norway. Photograph: Ange/Alamy

Historians had long assumed that, if the incident actually happened, the dead man was a Birkebeiner, and that the attackers most likely acted to humiliate the king, or to contaminate the water in the well in an early form of biological warfare.

Then, in 1938, archeologists excavating the well found, about 7 metres down the shaft and buried beneath multiple layers of stones, a human skeleton. But the second world war came, the German army occupied the area, and “well man” stayed where he was.

In 2014 and 2016, researchers led by Petersén resumed the excavation and, beneath further mounds of rubbish dumped down the well by the Nazi forces, managed to partially exhume the remains, identifying a male aged between 30 and 40.

He had been about 1.75 metres tall and hurled into the well wearing only a leather shoe, and short of a foot and his left arm. His skull – found separated from his body – bore a blunt force injury and sharp cuts that were probably inflicted before he died.

Determined to “provide independent sources of information about events in the historical record”, combining literary, historical, archaeological and scientific data, the research scientists have now discovered a great deal more about the man.

Radiocarbon dating of bone from the skeleton “produced a conventional radiocarbon age of 940, plus or minus 30 years”, they said in their paper – consistent with the date of the Baglers’ attack on Sverrisborg castle as described in the Sverris saga.

The team tried to sequence the man’s genome from his bones, but found the DNA had not been adequately preserved. Instead, Martin Ellegard of the Norwegian University of Science and Technology, obtained a DNA sample from one of the well man’s teeth.

Analysis revealed he had a medium skin tone, blond or light brown hair and blue eyes. Comparing his genome with those of modern Norwegians, with the help of the Icelandic firm deCode Genetics, showed the man was from southern Norway.

That was a surprise, because Sverre’s men were from central Norway: the southern besiegers may have thrown one of their own into the well.

Either way, the researchers believe this may be the first time that genomic information has been recovered from a specific character – or even an actual person – described in a saga.

The well man’s identity may not be 100% certain. But at the very least, “modern-day inferences based on ancient DNA” will have added to “the interpretation of historical events”, the researchers said. Genetic science is “enriching history, and helping separate fact from fiction”.