Biography of William Cavendish-Bentinck 3rd Duke Portland 1738-1809

On 11th June 1734 [his father] William Bentinck 2nd Duke Portland [aged 25] and [his mother] Margaret Cavendish Harley 2nd Duchess Portland [aged 19] were married at St Peter aka Oxford Chapel Vere Street Marylebone [Map]. She by marriage Duchess Portland. She the daughter of [his grandfather] Edward Harley 2nd Earl of Oxford and Earl Mortimer [aged 45] and [his grandmother] Henrietta Cavendish Holles Countess of Oxford and Mortimer [aged 40]. He the son of Henry Bentinck 1st Duke Portland and Elizabeth Noel Duchess Portland [aged 46]. They were sixth cousins.

On 14th April 1738 William Cavendish-Bentinck 3rd Duke Portland was born to [his father] William Bentinck 2nd Duke Portland [aged 29] and [his mother] Margaret Cavendish Harley 2nd Duchess Portland [aged 23] at Welbeck Abbey, Nottinghamshire [Map].

In 1759 [his brother-in-law] Thomas Thynne 1st Marquess of Bath [aged 24] and [his sister] Elizabeth Bentinck Marchioness Bath [aged 23] were married. She by marriage Viscountess Weymouth. She the daughter of [his father] William Bentinck 2nd Duke Portland [aged 49] and [his mother] Margaret Cavendish Harley 2nd Duchess Portland [aged 43]. They were third cousins.

On 1st May 1762 [his father] William Bentinck 2nd Duke Portland [aged 53] died. His son William [aged 24] succeeded 3rd Duke Portland, 4th Earl of Portland.

On 28th May 1763 [his brother-in-law] George Grey 5th Earl Stamford 1st Earl Warrington [aged 25] and [his sister] Henrietta Bentinck Countess Stamford and Warrington [aged 26] were married. She by marriage Countess Stamford. She the daughter of [his father] William Bentinck 2nd Duke Portland and [his mother] Margaret Cavendish Harley 2nd Duchess Portland [aged 48]. He the son of Henry Grey 4th Earl Stamford [aged 47] and Mary Booth Countess Stamford [aged 59].

On 8th November 1766 William Cavendish-Bentinck 3rd Duke Portland [aged 28] and Dorothy Cavendish 3rd Duchess Portland [aged 16] were married. She by marriage Duchess Portland. She the daughter of William Cavendish 4th Duke Devonshire and Charlotte Elizabeth Boyle Marchioness Hartington. He the son of William Bentinck 2nd Duke Portland and Margaret Cavendish Harley 2nd Duchess Portland [aged 51]. They were half fourth cousins.

On 23rd June 1768 [his son] William Henry Cavendish-Scott-Bentinck 4th Duke Portland was born to William Cavendish-Bentinck 3rd Duke Portland [aged 30] and [his wife] Dorothy Cavendish 3rd Duchess Portland [aged 17]. He married 4th August 1795 Henrietta Scott Duchess Portland and had issue.

On 7th June 1774 [his brother-in-law] William Cavendish 5th Duke Devonshire [aged 26] and Georgiana Spencer Duchess Devonshire [aged 17] were married at St Mary's Church, Wimbledon. It was her 17th birthday. She by marriage Duchess Devonshire. She the daughter of John Spencer 1st Earl Spencer [aged 39] and Margaret Georgiana Poyntz Countess Spencer [aged 37]. He the son of William Cavendish 4th Duke Devonshire and Charlotte Elizabeth Boyle Marchioness Hartington. They were fourth cousins.

On 14th September 1774 [his son] William Henry Cavendish-Bentinck was born to William Cavendish-Bentinck 3rd Duke Portland [aged 36] and [his wife] Dorothy Cavendish 3rd Duchess Portland [aged 24]. He married 19th February 1803 Mary Acheson, daughter of Arthur Acheson 1st Earl Gosford and Millicent Pole Countess Gosford.

On 3rd October 1775 [his daughter] Charlotte Cavendish-Bentinck was born to William Cavendish-Bentinck 3rd Duke Portland [aged 37] and [his wife] Dorothy Cavendish 3rd Duchess Portland [aged 25]. She married before 26th August 1832 her second cousin twice removed Charles Greville and had issue.

On 13th March 1779 [his daughter] Mary Cavendish-Bentinck was born to William Cavendish-Bentinck 3rd Duke Portland [aged 40] and [his wife] Dorothy Cavendish 3rd Duchess Portland [aged 28].

On 20th May 1780 [his son] Charles Cavendish-Bentinck was born to William Cavendish-Bentinck 3rd Duke Portland [aged 42] and [his wife] Dorothy Cavendish 3rd Duchess Portland [aged 29]. He married (1) 21st September 1808 Georgiana Augusta Frederica Seymour (2) 16th July 1816 Anne Wellesley Lady Abdy, daughter of Richard Wellesley 1st Marquess Wellesley and Hyacinthe Gabrielle Roland Marchioness Wellesley, and had issue.

On 2nd November 1781 [his son] Frederick Cavendish-Bentinck was born to William Cavendish-Bentinck 3rd Duke Portland [aged 43] and [his wife] Dorothy Cavendish 3rd Duchess Portland [aged 31]. He married 16th September 1820 Mary Lowther, daughter of William Lowther 1st Earl Lonsdale and Augusta Fane Countess Lonsdale, and had issue.

On 27th February 1782 [his brother-in-law] George Augustus Henry Cavendish 1st Earl Burlington [aged 27] and Elizabeth Compton Countess Burlington [aged 21] were married at London. She by marriage Countess Burlington. She the daughter of Charles Compton 7th Earl of Northampton and Anne Somerset Countess Northampton. He the son of William Cavendish 4th Duke Devonshire and Charlotte Elizabeth Boyle Marchioness Hartington. They were fourth cousins.

On 17th July 1785 [his mother] Margaret Cavendish Harley 2nd Duchess Portland [aged 70] died.

1792. Thomas Lawrence [aged 22]. Portrait of William Cavendish-Bentinck 3rd Duke Portland [aged 53].

On 3rd June 1794 [his wife] Dorothy Cavendish 3rd Duchess Portland [aged 43] died. She was buried at St Marylebone Church.

On 4th August 1795 William Henry Cavendish-Scott-Bentinck 4th Duke Portland [aged 27] and Henrietta Scott Duchess Portland [aged 21] were married. She by marriage Duchess Portland. He the son of William Cavendish-Bentinck 3rd Duke Portland [aged 57] and Dorothy Cavendish 3rd Duchess Portland.

In 1796 [his brother-in-law] George Grey 5th Earl Stamford 1st Earl Warrington [aged 58] was created 1st Earl Warrington, 1st Baron Delamer. [his sister] Henrietta Bentinck Countess Stamford and Warrington [aged 58] by marriage Countess Warrington.

On 19th February 1803 William Henry Cavendish-Bentinck [aged 28] and Mary Acheson [aged 16] were married. She the daughter of Arthur Acheson 1st Earl Gosford [aged 58] and Millicent Pole Countess Gosford [aged 53]. He the son of William Cavendish-Bentinck 3rd Duke Portland [aged 64] and Dorothy Cavendish 3rd Duchess Portland.

On 31st March 1807 William Cavendish-Bentinck 3rd Duke Portland [aged 68] was appointed Prime Minister.

On 21st September 1808 Charles Cavendish-Bentinck [aged 28] and Georgiana Augusta Frederica Seymour [aged 26] were married. She the daughter of King George IV of Great Britain and Ireland [aged 46] and Grace Elliott. He the son of William Cavendish-Bentinck 3rd Duke Portland [aged 70] and Dorothy Cavendish 3rd Duchess Portland.

On 30th October 1809 William Cavendish-Bentinck 3rd Duke Portland [aged 71] died. His son William [aged 41] succeeded 4th Duke Portland, 5th Earl of Portland.

1814. Benjamin West [aged 75]. Portrait of William Cavendish-Bentinck 3rd Duke Portland.