Lord Geoffrey Percy (1925-1984); youngest child of Alan Percy, 8th Duke of Northumberland, and Lady Helen Gordon-Lennox (1925–1984) Parents Helen Percy, Duchess of Northumberland Alan Percy, 8th Duke of Northumberland Children Diana Ruth Percy Siblings George Percy, 9th Duke of Northumberland Lady Diana Percy Hugh Percy, 10th Duke of Northumberland Elizabeth Douglas-Hamilton, Duchess of Hamilton and Brandon Lord Richard Percy Partners Mary Elizabeth Lea