Medici, Piero de', 1471–1503, Italian merchant prince. He succeeded his father, Lorenzo de' Medici (Lorenzo il Magnifico), as head of the Medici family and as leader of the Florentine state. In 1494 he surrendered the chief fortresses of Tuscany to the invading army of Charles VIII of France. The democratic party in Florence, led by Savonarola, took advantage of Charles's approach and of Piero's weakness to expel the Medici, who had virtually ruled Florence for half a century. After Piero's death the Medici regained (1512) control over Florence with the help of the Holy League. Giuliano de' Medici and Pope Leo X were brothers of Piero. Piero's son, Lorenzo de' Medici, became (1516) duke of Urbino.