The title "Duke of Cádiz" is a noble title in Spain, historically associated with the city of Cádiz. It was first created in 1810 by King Joseph Bonaparte, during the Peninsular War. The title has been held by various members of the Spanish royal family and nobility, often linked to the House of Bourbon. The current holder of the title is Alfonso de Borbón y Borbón, who is a descendant of the Spanish royal family. The title is part of the broader Spanish nobility system, which includes various ranks and titles that signify social status and historical significance in Spain.