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.