Leo X, originally Giovanni de' Medici 1475-1521
Italian pope

He was born in Florence. The second son of Lorenzo de' Medici, the Magnificent, and the brother of Piero de' Medici, he was created a cardinal at 13. Elected pope in 1513, he is best remembered as a patron of learning and the arts. He founded a Greek college in Rome and established a Greek press. His project for the rebuilding of St Peter's made it necessary to preach an indulgence in order to raise funds to do so and this provoked Martin Luther's 95 theses. Leo's failure to respond either promptly or effectively helped to increase the Reformation's early momentum. With his election as pope, the rule of Florence passed first to his younger brother, Giuliano, and then to his nephew, Lorenzo, Duke of Urbino. The real power of the family, however, remained with the pope and his cousin, Guilio, grandson of Cosimo de' Medici, who succeeded to the papacy in 1523 as Clement VII.

Bibliography: William Roscoe, The Life and Pontificate of Leo the Tenth (2 vols, 1853)