He was born on 13 April 1909 in Eynsford in Kent, the eldest son of Rev Canon Maurice Curteis Elphinstone, vicar of Sowerby Bridge (son of Sir Howard Warburton Elphinstone, 3rd Baronet) and his wife Christiana Georgina Almond (daughter of Hely Hutchinson Almond, former headmaster of Loretto School).
Due to this family connection, he attended Loretto School then won a place at Jesus College, Cambridge studying Mathematics, graduating BA in 1931.
[citation needed] During the Second World War he fought in the London Scottish Regiment and gained the rank of Major.
His final years in the war were spent in London doing statistical research under Francis Albert Eley Crew and Lancelot Hogben.
His proposers were Francis Albert Eley Crew, Sir Edmund Whittaker, Lancelot Hogben, and Alexander Aitken.