Vansittart was born in London 29 April 1766, the fifth son of Henry Vansittart, Governor of Bengal, and Emilia, daughter of Nicholas Morse, Governor of Madras. He died 8 February 1851 in Foot's Cray, Kent, having been created Baron Bexley in 1823. The peerage became extinct on his death. He was married once, to Catherine Isabella, second daughter of William eden, first Baron Auckland, in 1806. She died childless in 1810. He was first cousin to General George Henry Vansittart and Vice-Admiral Henry Vansittart, who served throughout the French wars. He joined the fashionable regiment, The City of London and Westminster Light Horse Volunteers, in 1797, and was promoted to lieutenant in 1798 and captain in 1799. His great-grandfather, Peter van Sittart, was a merchant adventurer who made a fortune in trade and moved from Danzig to London about 1670. The family was of Dutch origin, deriving its name from Sittart in Limburg.
From The Biographical Dictionary of British Economists in Oxford Reference.