William Cavendish-Bentinck, 3rd Duke of Portland British politician and prime minister (1738–1809) (1738–1809) Parents Margaret Cavendish Bentinck, Duchess of Portland William Bentinck, 2nd Duke of Portland Children Lord Charles Bentinck Lord William Bentinck Charlotte Cavendish-Bentinck William Bentinck, 4th Duke of Portland Frederick Cavendish-Bentinck Siblings Lord Edward Bentinck Elizabeth Bentinck Lady Henrietta Cavendish-Bentinck Partners Dorothy Bentinck, Duchess of Portland
