Medici, Ippolito de' (ēp-pôˈlētō dā mĕˈdĭchē, Ital. māˈdēchē) [key], 1511–35, cardinal of the Roman Catholic Church; an illegitimate son of Giuliano de' Medici, duke of Nemours. Pope Clement VII, head of the Medici family, ruled Florence through Ippolito, Ippolito's cousin, Alessandro de' Medici, and Cardinal Silvio Passerini. Clement increasingly favored Alessandro, and in 1531 he made him head of the republic. At the same time he made Ippolito a cardinal and sent him on a temporary mission to Hungary to remove him from the scene. In 1535, the Florentines deputed Ippolito to bring their grievances against Alessandro before Holy Roman Emperor Charles V. He died on his way, probably of malaria, although he may have been poisoned at Alessandro's command.