Scientists say they've solved 400-year-old murder case

ROME -- Italian scientists believe they have uncovered a 400-year-old murder.

Historians have long suspected that Francesco de' Medici, Grand Duke of Tuscany, and his second wife, Bianca Cappello, did not die of malaria but were poisoned -- probably by Francesco's brother, Cardinal Ferdinando de' Medici, who was vying for the title.

Now, forensic and toxicology experts at the University of Florence report evidence of arsenic poisoning in a study published in the British Medical Journal.

As rulers, art connoisseurs, and financiers of kings, the Medici family flourished for centuries in the rough and tumble alliances of old Europe, providing four popes and ruling first Florence then Tuscany from about 1430 to 1737.

Its most famous members include Lorenzo de' Medici, or Lorenzo the Magnificent, who supported Michelangelo, Leonardo da Vinci, and Sandro Botticelli. At least two Medici women -- Catherine and Maria -- married kings of France, and the Medicis' former home, Pitti Palace, now houses an important art gallery.

Francesco de' Medici ruled from 1574 until his death at age 46 on Oct. 17, 1587, 11 days after he fell ill and a few hours before his wife, who by all accounts had been his mistress while he was married to his first wife -- who is also believed to have died of poisoning.

"Immediately after their deaths, rumors began to circulate that they had been poisoned," Donatella Lippi, a professor and a co-author of the study, told the Associated Press.

From the outset, Ferdinando de' Medici's behavior was suspicious, the study says.

"There was always a suspicion [of murder], but there wasn't scientific proof," said Marcello Fantoni, who teaches Renaissance history at Kent State University.

Lippi and three other scientists -- Francesco Mari, Aldo Polettini, and Elisabetta Bertol -- tested a fragment of femur and beard hairs with skin tissue still attached taken from Francesco's tomb in the Medici Chapels in Florence. Bianca's grave was never found.

They also tested organ remains found in broken terra-cotta jars buried under the crypt in the Church of Santa Maria a Bonistallo, near Francesco's villa.

Lippi said DNA tests showed it was "highly probable" that one set belonged to Francesco. The other was female, Lippi said.

The tests showed acute arsenic poisoning, the researchers said.