Duchy of Florence

The Duchy of Florence was an Italian principality that was centred on the city of Florence, in Tuscany, Italy. The duchy was founded after Pope Clement VII, himself a Medici, appointed his relative Alessandro de' Medici as Duke of the Florentine Republic, thereby transforming the Republic of Florence into a hereditary monarchy. The second Duke, Cosimo I, established a strong Florentine navy and expanded his territory, purchasing Elba and conquering Siena. In 1569, Pope Pius V declared Cosimo Grand Duke of Tuscany. The Medici ruled the Grand Duchy of Tuscany until 1737. Origins and Constitution Florence had been under informal Medici control since 1434. During the War of the League of Cognac, the Florentines rebelled against the Medici, then represented by Ippolito de' Medici, and restored the freedom of their republic. Following the Republic's surrender in the Siege of Florence, Charles V, Holy Roman Emperor issued a proclamation explicitly stating that he and he alone could determine the government of Florence. On 12 August 1530, the Emperor created the Medici hereditary rulers (capo) of the Republic of Florence.