On 12 May 1748, Walpole married Lady Rachel Cavendish (1727 – 8 May 1805), the third daughter of the 3rd Duke of Devonshire, and on his death in 1809, his titles passed to their eldest son, Horatio.[1] Lord Orford and his wife had at least two other children: Lady Mary Walpole (born c. 1757), who married Thomas Hussey, 19th Baron Galtrim, on 4 August 1777 and had issue; and The Hon. George Walpole (20 June 1758 – May 1835).[1]
^ abcL. G. Pine, The New Extinct Peerage 1884-1971: Containing Extinct, Abeyant, Dormant and Suspended Peerages With Genealogies and Arms (London, U.K.: Heraldry Today, 1972), p. 211.