Malaria kills Medici brothers: DNA reveals 500‑year‑old mystery solved

Malaria kills Medici brothers

Recent ancient‑DNA work has finally answered a half‑↓ 500-year-old question about the deaths of two prominent members of the Medici dynasty. Researchers extracted genetic material from the skeletal remains of Cardinal Giovanni de’ Medici (d. 1562) and Grand Duke Francesco I de’ Medici (d. 1587) and found unmistakable traces of Plasmodium falciparum, the parasite that causes the deadliest form of malaria.

Historical accounts described the brothers’ illnesses as “tertian fever,” a pattern of high fevers recurring every third day—classic malaria symptomatology. The DNA evidence also uncovered a second parasite, Plasmodium malariae, in Francesco’s bones, indicating a mixed infection that likely intensified his condition.

“We can now state with scientific certainty that malaria, not poison, claimed the lives of these Medici figures,” said Valentina Giuffra, University of Pisa.

The strain infecting Giovanni is unprecedented: it carries two mutations never before documented in European samples, offering a rare glimpse into the pathogen’s evolution during the Renaissance. Evolutionary biologist Alexander Ochoa of Yale highlighted the broader implications, noting that such findings help map how malaria adapted over centuries.

These discoveries overturn centuries‑old rumors of arsenic poisoning and illustrate how marshy Tuscan estates, long‑standing breeding grounds for mosquitoes, served as silent killers well into the modern era. For further context on how ancient pathogens reshape modern science, see Reuters and Bloomberg.