Sir Dick White (1906–93) was a unique figure in the British intelligence services, as the only person to have headed both the Security Service and the Secret Intelligence Service. He joined the Security Service in January 1936 after being recruited by a friend who had joined the Service a couple of years earlier.
During the Second World War he was closely involved with operating the highly successful "Double Cross" system against Nazi Germany. He was responsible for recruiting his former history tutor, J. C. Masterman, who headed the committee responsible for the "Double Cross" system.
He became Deputy Director General in 1952 and succeeded Sir Percy Silitoe as DG in 1953. During his time in office he carried out a major reorganisation of the Service, in which the existing three divisions of the Service were replaced by six branches named A to F. His term was cut short in 1956 when the Prime Minister, Sir Anthony Eden, moved Sir Dick from the Security Service to head the Secret Intelligence Service. He retired from SIS in 1968.