Home Front Spies timeline
1939   Internment of enemy aliens means that many existing German spies are put in camps.
November Fougasse is asked to design a series of posters for the "Careless Talk Cost Lives" campaign.
1940 August British intelligence starts to intercept German intelligence signals.
June Government introduces fines of up to £50 for spreading panic rumours about spies.
3 September The first German 'invasion spies' arrive in Britain. All are captured within hours.
1941   MI5 now employs 868 people (an increase of over 700 since 1938).
January The XX Committee is established to run the British 'double cross' agent system.
December Codebreakers at Bletchley Park are able to break German code.
1942   Early 1942. The freelance double agent GARBO arrives in Britain. He leads many successful operations.
October The London Reception Centre is established. Its job is to identify spies entering the country disguised as refugees.
1943   Germans fail to realise that their spies are now double cross agents working for the British. The missions given to their spies reveal German military plans.
After the War   Study of German intelligence records shows that all 115 agents sent to Britain were identified and caught.