More than three centuries before Franklin D. Roosevelt, Henri was the first head of state to dream of putting a chicken in every pot.
For all his popularity, Henri came to a brutal end when on May 14 1610, aged 56, he was slashed twice in the throat by a Catholic fanatic who leapt out at him during a procession.
But his problems were only just beginning. In 1793, a revolutionary mob ransacked the royal chapel in Saint-Denis basilica, north of Paris, ripped open the tombs and put Henri's well-preserved corpse on display before beheading it. All the royal remains were tossed into a pit.
For the next couple of hundred years, a severed head touted as that of France's favourite king became a macabre curio, transferred among private collectors and only rarely surfacing in public.
In 1919, a Paris antiques dealer named Joseph-Emile Bourdais bought the skull at the Drouot auction house for three francs. He kept the head in a glass case, charging visitors a small fee to gawp at it.
When the Louvre declined to accept the head on his death, the relic was handed to Bourdais' sister, who kept it under her bed.
In 1955, she sold it to another collector, Jacques Bellanger, who wrapped it up in newspapers and left it in a wardrobe.
More than five decades later, with Bellanger an 84-year-old retired civil servant, it was tracked down through the diligence of a historian and a pair of TV journalists.
A positive identification has been made by Philippe Charlier, a 34-year-old professor of forensic pathology at the University Hospital Raymond Poincare in Garches.
Teasing out scraps of DNA from ancient relics, using 3D scanners, carbon dating and x-rays and testing minute samples for chemical signatures, Charlier has notched up a string of successes in historical whodunits.
The French media like to call him "the Indiana Jones of the cemeteries".
In 2007, Charlier determined that bones authenticated in 1909 by a papal commission as being the holy relics of Saint Joan of Arc, who was burned at the stake by the English, were those of an Egyptian mummy and a cremated cat.
In the remains of Diane of Poitiers, a favourite mistress of Henri II, Charlier found internal organs encrusted in gold. She had been taking the gold in the form of an elixir, apparently believing this would keep her young and beautiful.
He also concluded that a mummified heart held in Saint-Denis came from the uncrowned boy king Louis XVII - son of the guillotined Louis XVI - who died of disease in prison during the Revolution.
Charlier, who has just published a book entitled The Secret Dead of History, confirmed Henri's head through his red-and-white hair and the skull's perfect match with a death mask.
A dark lesion above the right nostril and a large hole in the right ear lobe, showing long use of an earring, were consistent with 16th-century portraits of the king.
Scanners and x-rays returned images of a wound in the left jawbone that had healed.
This was from a previous stabbing attempt, in 1594.
The head has been handed to Henri's descendant, Louis de Bourbon, Duke of Anjou and head of the overthrown Bourbon dynasty.
A 37-year-old Franco-Spanish banker who lives in Madrid, Louis is petitioning President Nicolas Sarkozy for the head to return to the royal crypt, which is officially the responsibility of the head of state.
The proposal was not a monarchy's bid to regain lost standing nor did it seek to divide the country, Louis told the daily Parisien.
"Henri IV reconciled warring parties. He was a very good example of a head of state whose first priority was to place the interests of the country over personal, partisan conflicts," he said.
"It is a good opportunity to reconcile the French with a troubled period of our history. We need national cohesion."
