Dorothy Bentinck, Duchess of Portland

Dorothy Cavendish was born on 27 August 1750 to William Cavendish, 4th Duke of Devonshire, the Prime Minister of Great Britain and his wife Lady Charlotte Boyle, 6th Baroness Clifford.

On 8 November 1766, Cavendish was married to William Cavendish-Bentinck, 3rd Duke of Portland. They were parents of six children:

• William Bentinck, 4th Duke of Portland (24 June 1768 – 27 March 1854)
• The Right Hon. Lord Charles William Cavendish Bentinck (1 July 1770 – 24 July 1770)[1]
• “The Duchess of Portland was safely delivered of a son, at his Grace’s house in Charles-street, Berkeley-square” on 25 August 1771.[2]
• Lord William Henry Cavendish-Bentinck (14 September 1774 – 17 June 1839)
• Lady Charlotte Cavendish-Bentinck (3 October 1775 – 28 July 1862). Married Charles Greville, and they had three sons: Charles Cavendish Fulke Greville, Algernon Greville, and Henry William Greville (1801–1872), and a daughter, Harriet (1803–1870) m. Francis Egerton, 1st Earl of Ellesmere
• Lady Mary Cavendish-Bentinck (13 March 1778 – 6 November 1843)
• Lord Charles Bentinck (3 October 1780 – 28 April 1826). Paternal grandfather of Cecilia Bowes-Lyon, Countess of Strathmore and Kinghorne
• Lord Frederick Cavendish-Bentinck (2 November 1781 – 11 February 1828) married Mary Lowther (d. 1863), daughter of William Lowther, 16 September 1820; had issue: George Cavendish-Bentinck
• A stillborn baby, birthed at Burlington House on 20 October 1786.[3]

According to newspaper accounts, she was the mother of nine children, only four of whom were living at the time of her own death.

The duchess died at her home, Burlington House, Piccadilly, and was buried in St Marylebone Parish Church, Marylebone, London. [4] She “died of a bowel complaint, which she had been subject to for many years, and which terminated in a mortification after a short illness. It was at first suspected, from the violent inflammation in her bowels, that her Grace had eaten water-gruel out of a copper saucepan not properly tinned; but this suspicion is certainly erroneous, as it proved on examination.”[5]

Bentinck is a great-great-great-grandmother of Queen Elizabeth II (see ancestry of Elizabeth II)