Testing old DNA is tricky, however, and too little DNA was recovered from the mummified head to entirely rule it out as Henry's, according to Cassiman and his colleagues.
King Henry's Head?
King Henry IV was king of the Pyrenees kingdom of Navarre in 1589, when an assassin killed his predecessor, Henry III. As a Protestant, Henry IV's ascension to the throne of Catholic France was complicated; he eventually converted to Catholicism, allegedly saying, "Paris is well worth a Mass."
In 1610, an assassin took Henry IV's life as well. He was buried in the Basilica of Saint Denis in Paris, but his rest may not have been so eternal. According to some accounts, Henry IV's grave was among those ransacked in 1793, when French revolutionaries took to mutilating dead monarchs as a statement against royal rule. As the disrupted graves were re-closed in the early 1800s, there's no way to verify whether Henry IV's body was beheaded at this time or left alone.
In 2010, osteo-archaeologist Philippe Charlier of University Hospital R Poincaré in Garches, France, and his colleagues reported that a forensic examination of a mummified head said to be Henry IV's was indeed the king's. Among the evidence: The mummy head has an irregular mole on the nostril and a pierced right ear, both features seen on contemporary portraits of Henry IV.