The Grand Duke of Tuscany was the title held by the ruler of the Grand Duchy of Tuscany, a historical state in central Italy. This title was established in the 16th century and lasted until the unification of Italy in the 19th century. The Grand Duchy was known for its cultural and artistic achievements, particularly during the Renaissance, and was home to notable figures such as Leonardo da Vinci and Michelangelo. The most famous Grand Duke was Cosimo I de' Medici, who ruled from 1537 to 1574 and significantly expanded the territory and influence of Tuscany. The Grand Duchy was eventually absorbed into the Kingdom of Italy in 1860, marking the end of its sovereignty.