In 1532, Pope Clement VII, who was born Giulio di Giuliano de' Medici, appointed Alessandro de' Medici as duke over the Republic of Florence, the Medici family having acted as "de facto" rulers over the city of Florence since 1434 when Cosimo "the Elder" de' Medici (also known by his supporters as "Pater Patriae", or "Father of the Country"), returned to the city from his short-lived exile in the Republic of Venice by the Alberti and Strozzi families who were also political rivals of the Medici family. The duchy would bolster Medici power and influence in the region, which had just a few years prior been restored by Emperor Charles V after political upheaval against the Medici pope and Medici rulers of Florence in 1527. Alessandro is also believed by historians to have been the illegitimate son of either Pope Clement VII or Lorenzo II de' Medici, Duke of Urbino.