Guy Liddell Guy Maynard Liddell , CB , CBE , MC ( 8 November 1892 – 3 December 1958 ) was a British intelligence officer . Biography . Early life & career . Liddell was born on 8 November 1892 at 64 Victoria Street , London , the son of Capt . Augustus Frederick Liddell RA , a retired Royal Artillery officer , and his wife Emily Shinner , who died when Liddell was eight years old . He was the younger brother of Capt . Cecil Frederick Joseph Liddell , who served as Head of MI5 ' s Irish section from 1939 , and David Edward Liddell ; and was a second cousin of Alice Pleasance Liddell , the child friend of Lewis Carroll who was the basis for the books " Alice ' s Adventures in Wonderland " and " Through The Looking Glass " . He was a talented cellist in his youth and was studying in Germany for a career as a professional musician when World War I began . During the conflict , he served with the Royal Field Artillery and was awarded the Military Cross . After the war , Liddell joined Scotland Yard where , in liaison with Special Branch and the Foreign Office , he was involved in breaking a spy ring based around the All Russian Cooperative Society in London . He married Hon . Calypso Baring , daughter of Cecil Baring , 3rd Baron Revelstoke of Membland , and Maude Louise Lorillard , on 7 April 1926 . They had one son and three daughters ; Peter Lorillard Liddell ( 9 Feb . 1927 - Apr . 2004 ) , Elizabeth Gay Liddell ( born 28 Feb . 1928 ) , Juno Liddell ( 29 Mar . 1930 – 13 Nov . 1968 ) and Maude Liddell ( baptised Anne Jennifer Liddell ) ( 16 May 1931 ) . He transferred to MI5 with his team in October 1931 , where he became an expert on Soviet subversive activities within the UK and recruited agents , including his private secretary Dick Wright , and future head of B5 ( b ) Maxwell Knight , in preparation for possible war with Germany . In 1936 he traveled to Washington where information he provided to FBI Director J . Edgar Hoover allowed the FBI to break a German spy - ring based around Gunther Rumrich . World War II . Following the outbreak of World War II , Prime Minister Winston Churchill sacked Director - General of MI5 Vernon Kell and in June 1940 Liddell was promoted to Director of B Division in charge of counter - espionage , where he appointed Dick Wright and Anthony Blunt to senior posts . Shortly after the new appointment , he was informed by Maxwell Knight of a suspected German spy - ring based around the Right Club of Archibald Ramsay and involving American cipher clerk Tyler Kent . Liddell met with U . S . Ambassador Joseph P . Kennedy Sr . , who agreed to waive Kent ’ s diplomatic immunity and he was successfully prosecuted , along with his handler , Anna Wolkoff . His agent , Duško Popov , provided an Abwehr questionnaire suggesting that the Japanese Air Force planned to attack the United States at Pearl Harbor . Popov was sent to FBI Director J . Edgar Hoover , who refused to take him seriously . Liddell was later criticized for not informing the Office of Naval Intelligence . His unhappy marriage to Hon . Calypso Baring was dissolved in 1943 after she had left him and joined her half - brother Lorillard Suffern Tailer in America . He subsequently fought a long legal battle for custody of their children . Later career . Liddell was expected to succeed Director General of MI5 , David Petrie , but was passed over when Home Secretary Herbert Morrison was informed by Ellen Wilkinson of rumors that he might be a double agent and was instead appointed Deputy - Director - General under Percy Sillitoe . These rumours were accentuated when his close friend Guy Burgess defected . He was also a known associate of other members of the Cambridge Five spy ring , Kim Philby and Anthony Blunt and in 1953 following an MI5 internal investigation he took early retirement and went to work as a security adviser to the Atomic Energy Authority . He died of heart failure in 1958 at his home , 18 Richmond Court , Sloane Street , London , and was buried at Putney Vale Cemetery . In 1979 , Goronwy Rees confessed to having been a Soviet spy , and named Liddell as the Fifth Man . Papers released since have all but completely cleared him of the charge , with the general academic consensus being that he was naïve in his friendships with some of his work colleagues . Wartime diaries . Liddell kept an almost daily diary containing details of his work at MI5 throughout World War II , dictated to , typed up and indexed by his secretary , Margot Huggins . Military historian Rupert Allason , writing under the " nom de plume " of Nigel West , has edited Liddell ’ s wartime diaries for publication in two volumes . In popular culture . Liddell was portrayed by Angus Wright in the 2003 BBC Television drama " Cambridge Spies " .