The illegitimate daughter of Richard Wellesley, first Marquess Wellesley; in 1812 she married Edward John Littleton, first baron Hatherton.

REFERENCES TO Lady Hyacinthe Mary Littleton [née Wellesley]:

Sydney Smith to Edward John Littleton, 7 November 1828 in A Memoir of the Reverend Sydney Smith. By his Daughter, Lady Holland. With a Selection from his Letters, edited by Mrs. Austin 2 vols (London: Longman, Brown, Green, and Longmans, 1855)

Countess of Cork to Lady Morgan, 3 April 1830 in Lady Morgan’s Memoirs: Autobiography, Diaries and Correspondence. Second Edition, Revised 2 vols (London: Wm. H. Allen & Co., 1863)