Medici siblings' deaths traced to malaria by ancient DNA study

Researchers from Yale University and the University of Pisa analyzed ancient DNA extracted from the skeletal remains of two Medici family members – Cardinal Giovanni de Medici, who died in 1562, and his brother Grand Duke Francesco de Medici, who died in 1587. Molecular tests identified DNA from the malaria parasites *Plasmodium falciparum* and, in the Grand Duke’s case, also *P. malariae*. A previously unknown strain of *P. falciparum* with two unique genetic mutations was recovered from the cardinal’s bones. The findings, published in *iScience*, overturn long‑standing theories that the brothers were poisoned with arsenic and demonstrate that malaria, known historically as “febre terzana,” was the true cause of death.

The study highlights the power of ancient DNA techniques for reconstructing disease histories and provides new data that may inform modern malaria research, a disease that the World Health Organization reports caused 610,000 deaths worldwide in 2024.