Scientists who exhumed the remains of several members of the Medicis, the clan that dominated the Florentine Renaissance, have conclusively dismissed the theory of family murders, solving a more than 400-year-old cold case.
Malaria, not poison as long rumored, killed Francesco I de' Medici, Grand Duke of Tuscany, and his second wife, Bianca Cappello, according to research to be published in Transactions of the Royal Society of Tropical Medicine and Hygiene.
The couple died a few hours apart in October 1587 after 11 days of agony. Their almost simultaneous deaths led to speculation that they had been murdered.
"It appears it wasn't poison. We carried an immunologic investigation and found evidence of the protozoan parasite Plasmodium falciparum. ... We are talking of the most deadly of the Plasmodium species that cause malaria," Gino Fornaciari, professor of forensic anthropology and director of the Pathology Museum at the University of Pisa, told Discovery News.
The founder of the Uffizi Gallery in Florence and a patron of the arts and sciences, Francesco (1541-1587) was more interested in alchemical experiments than dedicating himself to statecraft.
When his wife, Joan of Austria — the ugly daughter of Ferdinand of Habsburg — died, Francesco married his beautiful, long-time mistress Bianca Cappello (1548-1587). She lived only one day longer than he.
Although the original death certificates attributed the couple's demise to tertian malarial fever, rumors soon spread that Francesco's brother, Cardinal Ferdinando (1549-1609), had a hand in the their deaths. It was said that Ferdinando, who was at risk of being excluded from the succession, never tolerated the presence of the new Grand Duchess at the Medici court.
The rumors were further fueled by the fact that Francesco and Bianca fell ill a couple of weeks after Ferdinando came to the villa at Poggio a Caiano, near Florence, where the couple lived.
With Francesco's death, Ferdinando became Grand Duke — the last great Grand Duke of the Medici dynasty.
"He ruled with great skill and was the real beginner of a very rational trend in the government of Tuscany," Cristina Acidini, superintendent of Florence museums, told Discovery News.
A supporter of the arts, Ferdinando bolstered commercial and industrial activity, and arranged a series of strategic weddings in the family.
However, the controversial death of his brother remained a shadow over Ferdinando's legacy.
Ferdinando should be fully exonerated, according to Fornaciari, who in 2006 questioned the results of a toxicological study that pointed to arsenic poisoning as the cause of Francesco's death.
"I believe that the high arsenic concentrations found by the researchers were due to the frequent use of arsenic mixtures in embalming. Francesco died of pernicious malaria," Fornaciari said.
Fornaciari and colleagues detected Plasmodium falciparum's histidine-rich protein 2 in spongy bone samples belonging to Francesco, whose skeletal remains were unearthed from the Medici Chapels in Florence in 2004. Analysis could not be conducted on Bianca's remains since her burial site remains unknown.
The researchers used bones of Cosimo I de' Medici, Francesco's father who died of pneumonia, and Joan of Austria, Francesco's first wife who died in childbirth after producing her seventh child, as control samples.
As expected, Cosimo's and Joan's bones were all negative.
This study marks the first time that this immunological technique has been used to detect ancient P. falciparum proteins in bone samples.
"Muscle has been considered the best tissue for the detection of P. falciparum malaria because of its abundant red cell content," anthropologist Raffaella Bianucci, at the department of Anatomy, Pharmacology and Legal Medicine of Turin University, told Discovery News.
"Obtaining a positive result in bone samples is important because it opens new possibilities to test ancient skeletons," said Bianucci, who identified the traces of the parasite in Francesco's bones.