Graham Wellesley was born in 1965, the son of Garret Wellesley, 7th Earl Cowley, and his first wife, (Elizabeth) Suzanne Lennon. He has an elder sister, Lady Tara (born 1962). He is a descendant of Henry Wellesley, 1st Baron Cowley, brother of the Duke of Wellington.
Granville George Leveson-Gower, 2nd Earl Granville, KG PC FRS (11 May 1815 – 31 March 1891), styled Lord Leveson until 1846, was a British Liberal statesman and diplomat from the Leveson-Gower family. He is best remembered for his service as Secretary of State for Foreign Affairs.