First ever history of MI5 published in Britain

London — The first official history of Britain’s MI5 was published Monday, ending 100 years of secrecy over the counter-intelligence agency during two World Wars, the Cold War and the current fight against Islamic extremism.

The Defence Of The Realm is by Cambridge University historian Christopher Andrew, who had virtually unrestricted access to 400,000 files — and even joined the agency himself for nearly seven years.

The book’s revelations include that MI5 officers told then British premier Neville Chamberlain in 1938 that Adolf Hitler privately called him an "arsehole", after he appeased the Nazi regime over its annexation of the Sudetenland.

It also features previously unseen surveillance pictures of Soviet agents, Irish Republican Army (IRA) operatives and Islamic extremists plotting and shopping for explosives.

Andrew said he had been "pretty thrilled and a bit nervous" to write the book, which is more than 1,000 pages long.

"Every other day, I would say: ‘Oh crikey, I never knew that,’" he told reporters at a press conference.

Stephen Lander, the former head of MI5, or ‘M’, who commissioned the book in 2002, said he thought MI5 was the first Western intelligence agency to undertake this kind of project.

"This is quite shortly after 9/11, we had staff out in Afghanistan," he said, explaining why he gave it the green light. "It’s quite clear within the service that our world has changed fundamentally … Maybe we didn’t appreciate at that stage the extent to which that change was going to affect us post the invasion of Iraq. But we certainly did see that we would need to gear up to a new sort of approach and a new sort of work and we would particularly need the support of the public in the work."

AFP/Expatica