The severed head of King Henri IV has been identified from the jumbled remains in the mass graves in Paris's Royal Basilica of Saint-Denis. A team of researchers used a host of scientific strategies to confirm the head's owner, who was killed in 1610.

During his two decades as king of France (and 37 years as king of Navarre), Henri IV accumulated many a pleasing epithet, including "Henri the Great," "the good king Henri" and "the Green gallant"—the latter being an homage to his reputed good looks and upstanding character. One of his most famous historic contributions was the 1589 Edict of Nantes, the decree that ended the country's civil war by giving religious freedom to Protestants.

But not everyone took a kind view of the monarch's religious tolerance, and he became the target of many assassination attempts. Henri IV was finally murdered in 1610 by a militant Catholic named François Ravaillac, who stabbed the king in the royal carriage.

 Henri IV was embalmed and then interred at the Basilica of Saint-Denis. But his—along with other royal graves there—was destroyed in 1793 during the French Revolution. The remains were mutilated and mixed together in mass graves.

The embalmed severed head (likely detached from the body by revolutionaries during the 18th-century upheaval) "had a light brown color, open mouth, and partially closed eyes," wrote a team of researchers that has now described the find. The group, led by Philippe Charlier, a forensic medical examiner and osteoarchaeologist at the University Hospital R. Poincaré, added: "The preservation was excellent, with all soft tissue and internal organs well conserved."

But the physiognomy alone was not enough to prove a match. And although there were traces of hair left on the head and face, the researchers lacked adequate mDNA material to run a genetic test. So they turned to other methods to confirm the regal provenance of the cranium, including the following:

•    Radiocarbon dating provided a 200-year window (1450 to 1650), which matched with Henri's life span (1553 to 1610).

•    Computed tomography (CT) scans of the head matched up nicely with details in a mould that was made just after the king's death (now at the Saint-Genevieve Library in Paris).

•    Raman spectroscopy showed traces of an amorphous carbon known as ivory black, which was used by the physician Pierre Pigray during the embalming process (specifically requested by the king to be "in the style of the Italians" rather than conforming to more typical French burial preparations). "This charcoal, obtained by anaerobic calcinations of animal bones, corresponds to that deposited by the surgeon Pigray on the surface of the cadaver to absorb decomposition fluids and putrefactive gases," the researchers noted.

The paper, entitled "Multidisciplinary medical identification of a French king's head (Henri IV)," was published online December 14 in the British Medical Journal and included work by some 20 experts. And King Henri IV might not be the last head of state's head to be identified, the researchers noted: "Similar methods could be used to identify all the other kings' and queens' skeletons lying in the mass grave of the basilica."

Image courtesy of Wikimedia Commons