Alastair Denniston
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.
Read more about Alastair Denniston: Early Life, World War I and Interbellum, World War II, Personal and Post-war Life, Honours and Awards