How a stab wound, a gashed nose and a pierced ear helped scientists identify a 400-year-old head as the skull of France's King Henri IV

Scientists believe they have identified a mummified head as belonging to France's King Henri IV who was assassinated in 1610 at the age of 57.

After nine months of tests, researchers say they have positively identified the monarch's embalmed head which was shuffled between private collections ever since it disappeared during the French Revolution in 1793.

Henry IV was assassinated by a Catholic fanatic as his coach became caught up in traffic congestion 400 years ago. He was buried in the Basilica of Saint Denis near Paris, but during the frenzy of the French Revolution, the royal graves were dug up and revolutionaries chopped off Henry's head, which was then snatched.

The head disappeared but resurfaced in 1919 when an antiques dealer bought it from an auction house for three francs. Ever since then it was kept in secretive private collections.

In their examinations of the monarch's head, they found features often seen in the king's portraits, including a dark wound above his right nostril.