William Cavendish, 4th Duke of Devonshire (1720-1764), was a British nobleman and politician. He served as the Prime Minister of Great Britain from 1756 to 1757, during a challenging period marked by the Seven Years' War. Known for his calm demeanor, he was a member of the Whig Party and held various political positions throughout his career. The Duke was also a prominent figure in the Cavendish family, known for their extensive estates, including Chatsworth House. He was an advocate for the arts and sciences, supporting figures like the architect Robert Adam and the painter Joshua Reynolds. His contributions to society extended beyond politics, influencing culture and architecture in Britain.