Medici murder mystery

Francesco de Medici, Grand Duke of Tuscany, and his wife, Bianca Cappello, died in 1587 of arsenic poisoning and not malaria, as was claimed at the time, according to a new study by Italian researchers.

Known as Francesco I, he ruled for 13 years before he died at age 46 at his villa at Poggio a Caiano, 11 days after falling ill. His second wife, Bianca, died the next day.

Francesco’s brother and heir apparent, Cardinal Ferdinando de Medici, ordered an autopsy on both bodies, and some of their internal organs were entombed in four terracotta jars in the crypt of a nearby church, Santa Maria a Bonistallo.

Because of the mystery and intrigue that has perpetually surrounded the Medici family, historians have long suspected poisoning. In particular, the symptoms reported at the time -- nausea, violent vomiting, cold sweats and intense gastric distress -- are consistent with arsenic poisoning.

The team of researchers, headed by forensic toxicologist Francesco Mari of the University of Florence, collected a fragment of a femur and a few beard hairs with one small fragment of skin tissue still attached from the tomb of Francesco I in the Medici Chapels in Florence. The burial site of Bianca is unknown.

Medical historian Donatella Lippi of the University of Florence also searched the Santa Maria a Bonistallo crypt, locating broken terracotta jars containing “dry, thick and crumbly material.”

DNA tests showed that some of the material from the crypt matched that from Francesco’s tomb, whereas the remainder was from a female.

The organ specimens from both sexes contained lethal doses of arsenic, according to the study, published in the current issue of the British Medical Journal.

Most experts think that Ferdinando was the culprit, because he had the most to gain. Some, however, speculate that Bianca was trying to poison Ferdinando, but inadvertently felled Francesco. Bianca then poisoned herself in remorse, they say.

thomas.maugh@latimes.com