The
Duke of Portland is a
peerage title created in 1716 for
William Henry Bentinck[?], who was already Earl of Portland. The
dukedom[?] came into the possession of the Cavendish-Bentinck family by marriage.
- 1st Duke of Portland: Henry Bentinck (1862-1726), duke 1716-1726
- 2nd Duke of Portand: William Bentinck (1708/9-1762), duke 1726-1762
- 3rd Duke of Portand: William Henry Bentinck, later Cavendish-Bentinck (1738-1809), duke 1762-1809
- 4th Duke of Portand: William Henry Cavendish Bentinck, later Scott-Bentinck, later Cavendish-Scott-Bentinck (1768-1854), duke (1809-1854)
- 5th Duke of Portand: William John Cavendish Cavendish-Scott-Bentinck (1800-1879), duke 1854-1879
- 6th Duke of Portand: William John Arthur Charles James Cavendish-Bentinck (1857-1943), duke 1879-1943
- 7th Duke of Portand: William Arthur Henry Cavendish-Bentinck (1893-1977), duke 1943-1977
- 8th Duke of Portand: Ferdinand William Cavendish-Bentinck (1888-1980), duke 1977-1980
- 9th Duke of Portland: Victor Frederick William Cavendish-Bentinck (1897-1990), duke 1980-1990.
The Dukedom of Portland became extinct on the 9th Duke's death, though the 9th Duke's distant cousin succeeded him as Earl of Portland.