Sarah Lennox (18 September 1705 – 25 August 1751), was born Sarah Cadogan as the eldest daughter of William Cadogan (since 1716 1st Baron Cadogan of Reading and since 1722 1st Earl Cadogan) and his wife Margaret Cecilia Munter. On 4 December 1719, she married Charles Lennox, Earl of March at The Hague and in 1723, Charles succeeded to his father's title of Duke of Richmond, whereupon Sarah became Duchess of Richmond. Sarah was Lady of the Bedchamber to Queen Caroline from 1724 to 1737.
She and her husband had twelve children:
Lady Georgiana Carolina Lennox (27 March 1723 – 24 July 1774), married Henry Fox, 1st Baron Holland, and had issue.
Lord Charles Lennox (3 September 1724 – 1724), Earl of March.
Lady Louisa Margaret Lennox (15 November 1725 – May 1728).
Lady Anne Lennox (27 May 1726 – 1727).
Lord Charles Lennox (9 September 1730 – November 1730), Earl of March.
Lady Emilia Mary Lennox (6 October 1731 – 27 March 1814), married first James FitzGerald, 1st Duke of Leinster, and had issue; and secondly William Ogilvie and had issue.
Charles Lennox, 3rd Duke of Richmond (22 February 1735 – 29 December 1806).
Lord George Lennox (29 November 1737 – 25 March 1805), General.
Lady Margaret Lennox (16 November 1739 – 10 January 1741).
Lady Louisa Augusta Lennox (24 November 1743 – 1821), married Thomas Connolly but had no issue.
Lady Sarah Lennox (14 February 1745 – August 1826), married first Sir Charles Bunbury, 6th Baronet, and had issue (although not by her husband, but by Lord William Gordon); and secondly George Napier by whom she had issue.
Lady Cecilia Lennox (28 February 1750 – 21 November 1769), unmarried.
In 1999, a six-part BBC miniseries based on the lives of her daughters aired in the U.K. It was called Aristocrats and the Duchess was played by Diane Fletcher.
