A major new exhibition in partnership with MI5 has opened at The National Archives, Kew, offering an unprecedented look inside Britain’s domestic intelligence agency.
‘MI5: Official Secrets’ marks the first time in the agency’s 115-year history that it has collaborated so extensively on a public exhibition. With unique insights and contributions from MI5 itself, the exhibition explores the evolution of espionage in Britain and the agency’s response to shifting national security threats.
Now open to the public as of 2 April 2025, MI5: Official Secrets invites visitors to journey through some of the most pivotal moments in MI5’s history – from its founding in the lead-up to the First World War, through the battle against fascism during the Second World War, the intrigue of Cold War espionage, and into the present-day challenges of counter-terrorism.
Drawing on The National Archives’ rich holdings, the exhibition showcases original case files, photographs, and internal papers—some never before seen—alongside genuine espionage equipment used by spies and counter-intelligence officers over more than a century.
Among the remarkable documents now on public display are newly released papers including a first-hand account of Kim Philby’s 1963 confession and records relating to Cambridge spy Anthony Blunt.
Visitors will also encounter exclusive video interviews with former Directors General of MI5, intelligence historians such as Professor Christopher Andrew (author of MI5’s official history), and Baroness May, former Prime Minister and one of the UK’s longest-serving Home Secretaries.
Sir Ken McCallum, Director General of MI5, commented:
“We are pleased to partner with The National Archives to share our history through MI5: Official Secrets. While much of our work must remain secret, this exhibition reflects our ongoing commitment to being open wherever we can.”
Saul Nassé, Chief Executive and Keeper at The National Archives, added:
“It’s a privilege to work with MI5 on this exhibition, exploring the extraordinary story of what they do. As the official archive for the UK Government, we already make MI5 files available in our reading rooms and online. This exhibition builds on that by offering an immersive experience that will challenge perceptions and uncover surprising truths. Expect to get the inside track on famous spy scandals and discover secrets that will amaze you.”
Curator and historian at The National Archives, Mark Dunton, said:
“The joy of the MI5 files is that many read like gripping spy novels – but these are the real, official records. We’ll be shedding light not just on well-known cases such as the Cambridge Five, Klaus Fuchs, and the Second World War double agents, but also on the remarkable individuals behind the scenes: figures like Major ‘Tin Eye’ Stephens and Jane Sissmore, MI5’s first female officer. Even the Girl Guides, who acted as messengers in the agency’s early years, have their place in this extraordinary story.”
The exhibition also spotlights MI5’s early pioneers, including Vernon Kell, its first and longest-serving director, and William Melville, a key figure in shaping modern intelligence work. Visitors can explore cases involving the Portland Spy Ring, the infiltration of the Communist Party of Great Britain, and the changing face of surveillance and espionage techniques throughout the decades.
MI5: Official Secrets is now open at The National Archives in Kew.
To plan your visit and find out more, please go to: www.nationalarchives.gov.uk/mi5-official-secrets