Scientists Crack 300-Year-Old Mystery of King Louis XIV’s Death

Louis XIV ruled France for more than seven decades, transforming the nation into Europe’s cultural superpower and building the glittering Palace of Versailles. When he died on September 1, 1715—just days shy of his 77th birthday—his physicians concluded gangrene had eaten away at his leg.

But a team of French scientists now says that was wrong. According to new research published by The Times and Le Parisien, microscopic DNA analysis of the king’s preserved heart reveals fungal material, not bacteria, suggesting the monarch succumbed to a disease unknown to 18th-century medicine: chromoblastomycosis.

“It’s an infection caused by fungi that enter through the skin and can slowly spread through the bloodstream,” said Philippe Charlier, the French pathologist who led the study. “By analyzing the blood residues still present around the heart, we realized it wasn’t bacteria at all, but fungi. That changes everything.”

Historians say Louis XIV suffered through weeks of agony before his death, stoically enduring what courtiers described as “the ruin of his body.” The Duke of Saint-Simon, a nobleman at Versailles, wrote that the king “watched with firmness this spectacle of his own ruin,” never once complaining as infection ravaged his leg.

At the time, physicians could not have understood what they were seeing. Chromoblastomycosis—identified centuries later by the World Health Organization—would have been mistaken for gangrene. The new evidence suggests the fungal disease may have triggered septicemia, or blood poisoning, sealing the monarch’s fate.

The study was conducted after Louis XIV’s modern descendants, Jean d’Orléans and Louis-Alphonse de Bourbon, granted researchers permission to examine a small section of the king’s heart. The relic, encased in a golden urn, has been stored for centuries in the Basilica of Saint-Denis in Paris, the traditional resting place of French royalty.

For the descendants, the findings are more than a medical revelation—they are a window into the king’s final hours.

“The exact medical cause of his death is an additional element to understand the last moments of the sovereign,” Louis-Alphonse de Bourbon told Le Parisien. “It allows us to imagine whether he suffered or was able to pass away peacefully.”

Louis XIV, remembered as the “Sun King,” left behind a France forever changed—lavish, powerful, and deeply scarred by war and debt. His death marked the end of an era of absolute monarchy, ushering in decades of turmoil that would culminate in the French Revolution.

Now, three centuries later, science has illuminated his final mystery. The monarch who made France shine brighter than any other court in Europe died not from decay, but from a hidden invader—a fungus that outlasted empires.

Source: The Times (UK), Le Parisien, Mayo Clinic, World Health Organization