DNA Evidence Debunks a Longstanding Myth About Louis XVI's Blood

When King Louis XVI was beheaded in the early days of the French Revolution, it is said that a handkerchief soaked in his blood was placed in this gourd (pictured). Now a group of Spanish geneticists have sequenced DNA in the blood, to find out whether it's truly from the king.

First, the researchers sequenced the genomes of two of the only known living descendants of Louis XVI's lineage. These sequences would give them a sense of what kinds of genetic signatures they'd likely find in another member of the same family. Then they sequenced the DNA found in the blood-soaked cloth. The results suggest, perhaps not suprisngly, that the blood belongs to somebody else.

Write the researchers in Nature today:

We found that the ancestry of the gourd's genome does not seem compatible with Louis XVI's known ancestry. From a functional perspective, we did not find an excess of alleles contributing to height despite being described as the tallest person in Court. In addition, the eye colour prediction supported brown eyes, while Louis XVI had blue eyes. This is the first draft genome generated from a person who lived in a recent historical period; however, our results suggest that this sample may not correspond to the alleged king.

Whoever's DNA this is, he does not fit what the historical record tells us about the king. The DNA belonged to somebody who was likely not a tall person, and he had brown eyes. But many contemporary witnesses say king was tall with blue eyes. Of course it's possible that this sequence came from a contaminated sample, given that it has probably been handled by a lot of people over the centuries. And I suppose you could weave a conspiracy story that a patsy was killed in the king's place.

Or you could conclude what the researchers did: This artifact of violent revolution turns out to be symbolic rather than authentic.

Demystification of artifacts aside, this experiment is interesting because it's the first attempt that's been made to sequence the DNA of a figure from recent history. Previously, scientists have sequenced DNA from ice age individuals, as well as individuals from two early human groups, the Neanderthals and Denisovans. As ancient DNA sequencing gets cheaper, we may see more historical mysteries being investigated in genetics labs.

Read the full scientific paper in Nature