The Defence of the Realm: The Authorized History of MI5

*The Defence of the Realm* is an authorized history of MI5, the UK’s domestic counter-intelligence agency. It details its evolution, operations, and role in safeguarding national security from threats like espionage, terrorism, and subversion. The book offers insights into how MI5 balances intelligence gathering with civil liberties, highlighting key cases and organizational changes over time. Written with official approval, it provides a comprehensive, factual account aimed at readers interested in understanding the agency’s efforts to protect Britain from internal threats within a complex security landscape.