When the bones speak

S127 is a number that I won't forget in a hurry. That was the tomb that archaeologists uncovered in 2006, right in front of the entrance to St Peter's Church. At the time, Ghent's archaeologists and historians tentatively suggested the theory that this might be Judith, the first countess of Flanders. It was nothing more than a crazy hypothesis, but the ball really got rolling after the TV programme Het verhaal van Vlaanderen (The Story of Flanders).

Proving or disproving a theory like that is a step-by-step process. We could already tell with our naked eye that she was a woman due to the shape of her hip and we could also deduce from her remains that she was about fifty when she died. So far, so good. We know no biographical details about Judith as a historical figure after her marriage to Baldwin and the birth of her two children, but she certainly had to be older than twenty-five. Check.

At that point, things got more exciting with the biomolecular analysis. The underlying principle behind that type of analysis is that “You are what you eat”. From the ratio of chemical elements in the bone, we can tell what kind of diet a person was consuming, even in the case of someone who lived more than a thousand years ago. In this woman's case, her diet turned out to be exceptionally rich: lots of meat and fish, including sea fish and freshwater fish. From the decay in her teeth, we could also deduce that she loved sweets. Or that she liked drinking a glass too many – because alcohol also contains a lot of sugars.

So she was a wealthy person, then, who wanted for nothing. And more importantly, this had been true throughout her life. With most bodies from the early Middle Ages, the picture we get is rather different. Due to the fact that back then, many children endured a winter of deprivation at one time or another, we can see from their teeth that they sometimes stopped growing for a while. This is very similar to the growth rings in trees. If you look at a person's teeth, you can see that a thin line was formed the moment they started experiencing periods of hardship. But no such line could be seen in the teeth of the person in S127. This woman had feasted well throughout her life.

Up to this point, we shouldn't have been so surprised. After all, she was actually buried close to the entrance of St Peter's Church. Back then, this was a privilege granted only to persons of the very highest nobility, so it would have been bizarre if we had found a malnourished person buried there. So we returned to Professor Vanderputten: give us more. What else did we know, based on her life story?

That was when things got really exciting. Judith experienced an eventful childhood, he told us. At the age of 12, she was shipped from Senlis (near Paris) to Wessex, England, for a political marriage to King Ethelwulf. After his death, she had to marry her stepson, but he too died young. Having already been widowed twice, she returned to Senlis at the age of 16. To sum up, she left for England as a child and returned to these parts as an adolescent.

Thanks to techniques from forensic medicine – such as the ones seen in the CSI series – we were able to verify the story of her migration. The elements strontium and oxygen in your bones don't tell you what you ate, but actually where you ate. Biotopes are related to the soil where your food came from. We compared three teeth: a canine (which you get at the age of six or seven), a second molar (at the age seven to eight) and a third molar (which grows between the ages of twelve and sixteen).

Based on her life story, we would expect to find the same biotopes in the two oldest teeth, and a different biotope in the third. Waiting for the results was an extremely tense period. While we and the team were waiting for the lab results to come in, it was really nail-biting. And then everything fell into place! This woman had effectively migrated as a young adolescent. That kind of mobility was really something quite extraordinary, especially in the Carolingian period.

We now knew enough to switch to the most expensive technique – DNA analysis. Our colleague who is an expert in ancient DNA drilled into the middle ear to extract a sample. Unfortunately, however, the results were disappointing. The DNA was too severely damaged, so all that we got were some detached and damaged fragments. The only thing that this investigation revealed was that this was a human being, not an animal. But we'd already managed to ascertain that for ourselves, of course.

And are we now sure that after more than a thousand years, we actually found Judith under the cobblestones of St Peter's Square? No, we're not certain. But we also haven't been able to prove that this isn't her either. Hopefully, this won't be the end of the story. I have been working as a bioanthropologist for 12 years now, and I have already seen the technology in our field change tremendously. 

What I hope is that at some time in the future, bioinformatics will be able to produce more detailed results with the help of AI. So that we can repair those loose puzzle pieces of her DNA and link them together. If we had a complete DNA helix, we could go to the German city of Aachen, as that is where the remains of Charlemagne, Judith's great-grandfather, lie buried. A silly dream perhaps, but if we could compare the two... To be continued?