The title "Duke of Sicily" refers to a noble rank historically associated with the island of Sicily, which is the largest island in the Mediterranean Sea. The title was often held by rulers or vassals who governed the island during various periods, particularly during the Middle Ages and the Renaissance. The title has connections to several royal families, including the Normans and the Habsburgs. The title has evolved over time, reflecting the changing political landscape of Italy and the Mediterranean region. Today, the title is largely ceremonial and is not associated with any governing authority, as Sicily is now part of the Italian Republic.