William Charles Augustus Cavendish-Bentinck was born 3 October 1780 in Welbeck Abbey, Nottinghamshire, England, United Kingdom to William Henry Bentinck, 3rd Duke of Portland (1738-1809) and Dorothy Cavendish (1750-1794) and died 28 April 1826 Park Lane, Greater London, England, United Kingdom of blood aneurysm. He married Georgiana Augusta Frederica Seymour (c1787-1813) 21 September 1808 . He married Anne Wellesley (1788-1875) 23 July 1816 St Martin in Westminster, London, England, United Kingdom.
|Offspring of William Charles Augustus Cavendish-Bentinck and Georgiana Augusta Frederica Seymour (c1787-1813)|
|Georgiana Augusta Frederica Henrietta Cavendish-Bentinck (1811-1883)|