The eldest child of Lady Elizabeth Foster with her husband John Thomas Foster; he spent his later years as a country gentleman.

CORRESPONDENCE OF Frederick Foster:

Frederick Foster to Lady Melbourne, [November 1802] in In Whig Society 1775-1818: Compiled from the hitherto unpublished Correspondence of Elizabeth, Viscountess Melbourne, and Emily Lamb, Countess Cowper, afterwards Viscountess Palmerston (London: Hodder and Stoughton LTD., 1921)