Ancient DNA Clears Tuscan Noble of Poisoning

Researchers at Yale University determined that Francesco de' Medici, Grand Duke of Tuscany, died from malaria in 1587, not arsenic poisoning. For centuries, rumors circulated that his brother, Cardinal Fernando, poisoned him to seize power.

The study published in iScience analyzed DNA from Francesco, his brother Giovanni, and other malaria victims from the period. The Medici family rose to prominence in the 12th century through banking and patronage of the arts during the Renaissance, funding artists like Michelangelo and Botticelli.

Francesco, though a distrustful ruler, continued this tradition. Researchers found Francesco’s DNA contained traces of Plasmodium falciparum and P. malarie, confirming malaria as the cause of death.

The team also identified a previously unknown strain of P. falciparum in Giovanni, offering new insight into the parasite's historical diversity. Malaria was endemic in Italy for centuries, shaping its history until its eradication in 1950. The findings suggest malaria was more prevalent, and deadly, in Tuscany than in northern Italy.