Sarah Cadogan was born on 18 September 1706, at S'Gravenhage (The Hague), the eldest daughter and co-heir of William Cadogan, Earl Cadogan, and his wife Margaretta Cecilia Munter.
At the age of 13 she was married on 4 December 1719 to the 18 year old, Charles Lennox, 2nd Duke of Richmond, then known by the courtesy title of Earl of March, apparently to cancel out a gambling debt between their fathers. Sarah then returned to her parents, and the Earl of March continued on with his 'grand tour'.
The story goes that when he finally returned to England in 1722, instead of seeking out his wife, he went to the theatre, and espied a very beautiful young woman in one of the boxes. When he enquired who she was he was told that he must have been away for a long time, "not to know the toast of the town, the beautiful Lady March"; his wife.
It became an extremely happy and close marriage and they had twelve children.
Brydges, Sir Egerton. (1812). Collins's Peerage of England: genealogical, biographical and historical, Vol. 1. Retrieved from http://books.google.com.au
Cokayne, George Edward (Ed.). (1892). Complete Peerage of England, Scotland, Ireland, Great Britain and the United Kingdom, extant, extinct or dormant (1st ed. Vol. 4: G. to K.). London: George Bell & Sons. Retrieved from https://books.familysearch.org
Cokayne, George Edward (Ed.). (1893). Complete Peerage of England, Scotland, Ireland, Great Britain and the United Kingdom, extant, extinct or dormant (1st ed. Vol. 5: L. to M.). London: George Bell & Sons. Retrieved from https://books.familysearch.org
Cokayne, George Edward, Doubleday, H.A., White, Geoffrey H., & Lord Howard de Walden (Eds.). (1945). The Complete Peerage: or a history of the House of Lords and all its members from the earliest times (2nd ed. Vol. 10). London: St Catherine Press.
Tillyard, Stella. (1994). Aristocrats: Caroline, Emily, Louisa and Sarah Lennox 1740-1832. London: Vintage.
Thank you to Barry Meadows for creating Cadogan-13 on 10 Nov 13. Click the Changes tab for the details on contributions by Barry and others.