Duke of the Florentine Republic in the context of Medici family

Alessandro de' Medici (22 July 1510 – 6 January 1537), nicknamed "il Moro" due to his dark complexion, Duke of Penne and the first Duke of the Florentine Republic (from 1532), was ruler of Florence from 1530 to his death in 1537. The first Medici to rule Florence as a hereditary monarch, Alessandro was also the last Medici from the senior line of the family to lead the city. His assassination at the hands of distant cousin Lorenzaccio caused the title of Duke to pass to Cosimo I de Medici, from the family's junior branch.

This is a list of grand dukes of Tuscany. The title was created on 27 August 1569 by a papal bull of Pope Pius V to Cosimo I de' Medici, member of the illustrious House of Medici. His coronation took place in Rome on 5 March 1570 by the hands of the Pope himself.

Cosimo's family, the Medici dynasty, had been ruling the Florentine Republic, the predecessor of the Grand Duchy of Tuscany, since 1434, first as Lords of Florence and later as Dukes. The title of Grand Duke, was in fact the second title of recognition within the Tuscan politics given by a Pope to the Medici family, the first being that of Duke of the Florentine Republic, created by Pope Clement VII in 1532.