Sir Richard held the title of Lord Yarmouth; he succeeded his father as Marquess of Hertford in 1842. He also took his father's post in the House of Lords, voting with the Conservative party. Seymour-Conway was attached to the embassy in Paris in 1817, and in 1829, the embassy at Constantinople. For the most part, he lived in Paris, where he owned several houses, and is said to have had the largest fortune in England. The Marquess was named a Knight of the Order of the Garter in 1846, and in 1855, received the cross of a Commander of the Legion of Honour for his encouragement of the arts. A Captain in the British Army, he died unmarried and was thus succeeded by his cousin as 5th Marquess. It has been convincingly suggested that his secretary, Sir Richard Wallace [1818-1890], 1st Bt., was his illegitimate son by a Mrs. Agnes (Wallace) Jackson.
Vapereau, Gustave. Dictionnaire universel des contemporaines. 4th ed. Paris, London, and Leipzig, 1870: 888.