PISA, ITALY—Testing of Giovanni de’ Medici’s bones has shown that the mercenary soldier died of gangrene, and not an improperly amputated leg, as had been rumored. Known as Giovanni of the Black Bands for the black bands of mourning he wore after the death of Pope Leo X, he was hit be a cannon ball during a battle when he was 28 years old. “The leg was already partially amputated by the cannon ball, so the surgeon simply completed the amputation by cleaning the wound and smoothing the stump,” said Gino Fornaciari of the University of Pisa.