Legend has it that when France’s King Louis XVI was killed via guillotine some 200 years ago during the French Revolution, someone used a handkerchief to soak up the king’s blood, then stored the handkerchief in a gourd. DNA has confirmed this to be true, thanks to efforts by paleogenomic researchers, as published in the journal Forensic Science International.

The gourd, which is in the possession of a wealthy Italian family, is emblazoned with figures from the French Revolution, and an inscription:

“On January 21, Maximilien Bourdaloue dipped his handkerchief in the blood of Louis XVI after his decapitation.”

The handkerchief has since disintegrated, but the dried blood remained in the gourd, from which intact DNA has been extracted and compared with DNA extracted from the embalmed head of 16th-century King Henry IV, a direct paternal ancestor. Y chromosome markers confirmed the paternal relationship, with the specific alleles being identified as characteristic of the Bourbon region of France, and which are very rare in Europe today.

Y-chromosome comparison testing, such as the paternal lineage test offered by DNA Diagnostics Center, relies on the fact that the Y chromosome is passed from father to son relatively unchanged through many generations. Therefore, men from the same paternal lineage would have the same genetic markers in their Y chromosome, even if they are separated by several generations–200 years, in the case of Henry IV and Louis XVI. (For more information about ancestry testing, visit HomeDNA.com.)

That the gourd still contained viable DNA for DNA testing is an awesome testament to DNA’s resilience. Interested readers should be advised, however, that their best chances of preserving DNA for future use and testing is to use DDC’s DNA banking services, which uses methods a bit more reliable than storing blood in a gourd.