When was MI5 founded and what was its original name?
MI5 began as the Home Section of the Secret Service Bureau founded in 1909. It started with a small staff working alongside Special Branch of the Metropolitan Police.
Questions about MI5
Short answers, pulled from the story.
Who arrested twenty-one spies on the day after the declaration of the First World War?
Home Secretary Reginald McKenna announced that no fewer than twenty-one spies had been arrested in various places across Britain on the day after the declaration of the First World War. Vernon Kell sent letters to local police forces on the 29th of July to warn them of impending arrests.
What is the Double-Cross System used by MI5 during the Second World War?
The Double-Cross System originated from an internal memo drafted by an MI5 officer in 1936 that criticized the policy of prosecuting all captured enemy agents. MI5 offered captured agents the chance to work as double-agents if they agreed to transmit bogus information back to their handlers.
Which spy ring did MI5 fail to detect until after World War II?
The most significant failure of the post-war era involved the inability to detect the Cambridge Five spy ring formed during inter-war years. Members included Kim Philby Donald Maclean Guy Burgess Anthony Blunt and John Cairncross.
How many individuals were held in files by MI5 when revealed in 2015?
MI5 held files on 272,000 individuals representing one in every 160 adults when it was announced by Home Secretary in 2015. A traffic light system categorizes these records into three categories with green active files accounting for about 10 percent.