Medici, Alessandro de'

(born 1510/11, Florence—died Jan. 5–6, 1537, Florence) First duke of Florence (1532–37). A member of the elder branch of the Medici family, he was probably the illegitimate son of Cardinal Giulio de' Medici (later Pope Clement VII). The pope made Cardinal Passerini regent in Florence for Alessandro, but they were forced to flee when the unpopular regency provoked a revolt in 1527. An agreement between the pope and Emperor Charles V restored the Medici in Florence (1530), and Alessandro was declared a hereditary duke (1532). A tyrannical ruler, he sought to solidify his control by marrying Charles V's daughter, Margaret of Austria, in 1536. In an unsuccessful attempt to cause a revolt, a distant cousin, Lorenzino de' Medici (1514–48), murdered Alessandro in 1537.