The Republic of Florence was a state that was centered on the Italian city of Florence in Tuscany. The republic originated in 1115, when the Florentine people rebelled against the Margraviate of Tuscany upon the death of Matilda of Tuscany, who controlled vast territories that included Florence. The Florentines formed a commune in her successors' place. Cosimo I, established a strong Florentine navy and expanded his territory, conquering Siena in 1555. In 1569, the Pope declared Cosimo the first Duke of Tuscany. The Medici ruled the Grand Duchy of Tuscany until 1737.
