Hugh Algernon Percy, 10th Duke of Northumberland, (6 April 1914 – 11 October 1988), was the son of Alan Percy, 8th Duke of Northumberland, and Lady Helen Gordon-Lennox. He succeeded to the dukedom of Northumberland in 1940, when his brother Henry, the 9th Duke, was killed in Belgium in World War II during the retreat to Dunkirk.
Lord Lieutenant of Northumberland from 1956 to 1984Chancellor of the University of Newcastle from 1964 to 1988Chairman of the Medical Research Council from 1969 to 1977President of the Royal Agricultural Society of England in 1956 and 1962Chairman of the Agricultural Research Council from 1958 to 1968Chairman of the Committee of Enquiry on Foot and Mouth DiseaseLord Steward of H.M. Household from 1973 to 1988Master of the Percy Foxhounds from 1940 to 1988He was commissioned into the Northumberland Hussars. In 1940, as a Lieutenant, he transferred to the Royal Artillery. In 1947, as a Captain, he transferred back to the Northumberland Hussars.
Northumberland married Lady Elizabeth Diana Montagu Douglas Scott (died 19 September 2012), daughter of Walter Montagu Douglas Scott, 8th Duke of Buccleuch, on 12 June 1946. They had seven children:
Lady Caroline Mary Percy (b. 3 May 1947), married Pierre, Comte de Cabarrus on 12 January 1974 and had issue:Chiara de Cabarrus (22 November 1974)Diana de Cabarrus (b. 1977) married Alexander Baillie on 25 March 2017 Lady Victoria Lucy Diana Percy (b. 19 April 1949), married Aidan Cuthbert on 4 October 1975 and divorce had issue. Then remarried to Charles Lyon Fellowes in 2000 and divorce in 2006.Alice Cuthbert (1978)Lucy Cuthbert (1982) married Prince Khalid of Saudi Arabia on 28 March 2011.Molly Cuthbert (1984)David Cuthbert (1987)Lady Julia Helen Percy (b. 12 November 1950), married Nicholas Craig Harvey on 11 June 1983 and had issue:Georgina Craig Harvey (20 May 1986)Christopher Craig Harvey (4 October 1988)Laura Craig Harvey (7 September 1992)Henry Alan Walter Richard Percy, 11th Duke of Northumberland (1 July 1953 – 31 October 1995)Ralph George Algernon Percy, 12th Duke of Northumberland (b. 16 November 1956), married Jane Percy, Duchess of Northumberland (née Jane Richard) and had issueLady Louise Percy (25 May 1962 – 27 May 1962)Lord James William Eustace Percy (b. 18 June 1965), married Lucy Caroline Rugge-Price and had issue:Thomas Hugh Percy (2001)Eliza Rose Percy (2003)Willa Katherine Percy (2005)Samuel James Edward Percy (2008)