Murder in cold blood? Forensic and bioarchaeological identification of the skeletal remains of Béla, Duke of Macsó (c. 1245–1272)

In 1915, the remains of a male were discovered in a 13th-century monastery on Margaret Island, Budapest. Historical context suggested that the remains may belong to Duke Béla of Macsó (c. 1245–1272), grandson of King Béla IV of Hungary (House of Árpád) and son of Duke Rostislav (Rurik dynasty). We applied a complex approach to identify the individual and reconstruct the circumstances of his death. Radiocarbon dating, when adjusted for freshwater reservoir effects linked to a high-protein diet, placed the burial in the mid-13th century. Skeletal features corresponded to a young adult male. Stable isotope and dental calculus analyses indicated a high-status diet rich in animal proteins and C3 cereals. Ancient DNA confirmed descent from King Béla III (Árpád dynasty) and Y-chromosomal affiliation with the Rurikid lineage. Forensic evidence revealed 26 perimortem injuries, suggesting a coordinated, premeditated assassination involving at least three assailants. The pattern of injuries indicates both planning and intense emotional involvement. Our findings provide the first genetic identification of a medieval royal, and resolve a century-old archaeological question, and illustrate the power of integrating multidisciplinary methods to confirm historical hypotheses and reconstruct violent deaths from the past with unprecedented detail.