Alastair Denniston

Olympic medal record
Men's field hockey
Bronze	1908 London	Team

Commander Alexander Guthrie (Alastair) Denniston CMG CBE RNVR (1 December 1881, Greenock – 1 January 1961, Milford on Sea) was a British codebreaker in Room 40 and first head of the Government Code and Cypher School (GC&CS) and field hockey player. Denniston was appointed operational head of GC&CS in 1919 and remained so until February 1942.^[1]

Contents 1 Early life 2 World War I and interbellum 3 World War II 4 Post-war life 5 Honours and awards 6 References 7 External links

Early life

Denniston was born in Greenock, the son of a medical practitioner.^[1] He studied at the University of Bonn and the University of Paris.^[1] Denniston was a member of the Scottish Olympic Hockey team in 1908 and won a bronze medal.

World War I and interbellum

In 1914 he helped form Room 40 in the Admiralty, an organisation responsible for intercepting and decrypting enemy messages. In 1917 he married a fellow Room 40 worker, Dorothy Mary Gilliat.^[1]

After World War I, Room 40 was merged with its counterpart in the Army, MI1b, to become the Government Code and Cypher School in 1919. Denniston was chosen to run the new organisation.

On July 26, 1939, just five weeks before the outbreak of World War II, Denniston was one of three Britons (along with Dilly Knox and Humphrey Sandwith) who participated in the trilateral Polish-French-British conference held in the Kabaty Woods south of Warsaw, at which the Polish Cipher Bureau initiated the French and British into the decryption of German military Enigma ciphers.^[2]

World War II

With the outbreak of World War II in 1939, GC&CS greatly expanded and relocated to Bletchley Park.

In February 1942, GC&CS was reorganised, and Denniston was placed in charge of a civil and diplomatic division in London, while Edward Travis succeeded him at Bletchley Park, overseeing the work on military codes and ciphers.

Post-war life

Denniston retired in 1945, and later taught French and Latin in Leatherhead.^[1]

Honours and awards

• 7 January 1918 appointed an Officer of the Order of the British Empire (OBE) Commander Alexander Guthrie Denniston, R.N.V.R. Naval Intelligence Division, Admiralty.^[3]

• 2 January 1933 appointed a Companion of the Order of the British Empire (CBE) Commander Alexander Guthrie Denniston, O.B.E., R.N.V.R. Head of a Department, Foreign Office.^[4]

• 12 June 1941 appointed a Companion of the Order of St Michael and St George (CMG) Commander Alexander Guthrie Denniston, C.B.E., R.N.V.R. (Retd.), Head of a Department of the Foreign Office.^[1][5]

References

• James Gannon, Stealing Secrets, Telling Lies: How Spies and Codebreakers Helped Shape the Twentieth Century, Washington, D.C., Brassey's, 2001, ISBN 1-57488-367-4.
• F. H. Hinsley and Alan Stripp, eds., Codebreakers: the Inside Story of Bletchley Park, Oxford University Press, 1993, ISBN 0-19-820327-6.
• Władysław Kozaczuk, Enigma: How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War II, edited and translated by Christopher Kasparek, Frederick, MD, University Publications of America, 1984, ISBN 0-89093-547-5, pp. 59–60.

External links

• The Papers of Alexander Guthrie Denniston are held at the Churchill Archives Centre in Cambridge, and are accessible to the public.
• DatabaseOlympics.com profile
• Thirty Secret Years: A. G. Denniston's work in signals intelligence 1914-1944

Government offices
New title	Deputy Director of GC&CS later Deputy Director (Diplomatic and Commercial) 1919–1945	Succeeded by Sir Edward Travis

Persondata
Name	Denniston, Alastair
Alternative names	Denniston, Alexander Guthrie (birth name)
Short description	British cryptographer and Royal Navy Commander
Date of birth	1 December 1881
Place of birth	Greenock, Scotland, United Kingdom
Date of death	1 January 1961
Place of death	Milford on Sea, Hampshire, England, United Kingdom