The Marquess of Newcastle is a title in the British peerage, first created in 1620 for Henry Cavendish. The title has been associated with the Cavendish family, who played significant roles in English history, particularly during the English Civil War. The title has been passed down through generations, often linked to the Duke of Newcastle. The Marquessate is part of the House of Lords, where peers have historically held influence in British politics. The current Marquess of Newcastle is David Cavendish, who succeeded his father in 1988. The family estate, Clumber Park, is a notable property associated with the title.