| Honorific Prefix: | Her Grace |
| The Duchess of Marlborough | |
| Birth Name: | Lady Caroline Russell |
| Birth Date: | 13 January 1743 |
| Death Place: | Blenheim Palace |
| Father: | John Russell, 4th Duke of Bedford |
| Mother: | Gertrude Leveson-Gower |
Caroline Spencer, Duchess of Marlborough (13 January 1743 - 26 November 1811), formerly Lady Caroline Russell, was the wife of George Spencer, 4th Duke of Marlborough.
Lady Caroline was born on 13 January 1743. She was the daughter of John Russell, 4th Duke of Bedford, and his second wife, the former Gertrude Leveson-Gower. Her father served as the British Ambassador to France and Lord President of the Council. Her brother was Francis Russell, Marquess of Tavistock (the father of her nephews Francis Russell, 5th Duke of Bedford, and John Russell, 6th Duke of Bedford).
Her paternal grandparents were Wriothesley Russell, 2nd Duke of Bedford and the former Elizabeth Howland (the daughter and heiress of John Howland of Streatham, Surrey). Her maternal grandparents were John Leveson-Gower, 1st Earl Gower and the former Lady Evelyn Pierrepont (a daughter of Evelyn Pierrepont, 1st Duke of Kingston-upon-Hull).[1]
On 23 August 1762, Lady Caroline was married to George Spencer, 4th Duke of Marlborough at Bedford House in Bloomsbury, London.[2] George was a son of Charles Spencer, 3rd Duke of Marlborough and the former the Hon. Elizabeth Trevor (daughter of Thomas Trevor, 2nd Baron Trevor). Together, they were the parents of:
The Duchess died at Blenheim Palace on 26 November 1811. The Duke died on 29 January 1817.[3]
A letter survives from Caroline to Ozias Humphrey, which has been approximately dated to 1788. In it, she refers to a portrait drawing of her husband by Thomas Gainsborough. Gainsborough having died in 1788, she asks Humphrey to complete the painted portrait.[4] Caroline and her husband were also painted together by William Austin. Her own portrait, as a child, had been painted by Jean-Étienne Liotard around 1754. She was also painted by Sir Joshua Reynolds around the time of her marriage,[5] and later, with her eldest daughter.[6]
Queen Charlotte is reputed to have called Caroline "the proudest woman in England".[7] She died on 26 November 1811 and was buried at Blenheim Palace.