The Secret History of MI6 - Keith Jeffery

The authorized history of the world's oldest and most storied foreign intelligence service, drawing extensively on hitherto secret documents

Britain's Special Intelligence Service, commonly called MI6, is not
only the oldest and most storied foreign intelligence unit in the
world - it is also the only one to open its archives to an outside
researcher. The result, in this authorized history, is an unprecedented
and revelatory look at an organization that essentially created, over
the course of two world wars, the modern craft of spying. Here are the true stories that inspired Ian Fleming's James Bond's novels and John le Carr George Smiley novels. Examining
innovations from invisible ink and industrial-scale cryptography to
dramatic setbacks like the Nazi sting operations to bag British
operatives, this groundbreaking history is as engrossing as any
thriller - and much more revealing.

"Perhaps the most authentic account one will ever read about how intelligence really works." -The Washington Times