A clear case of genius: room 40's code-breaking pioneer

In 1933 the Admiralty banned Admiral Sir Reginald 'Blinker' Hall from publishing his autobiography, but here those chapters that survived are presented in full.

See what the renowned spymaster had to say about British Naval Intelligence - the pinnacle of the world's secret intelligence services.

He explores the function of secret intelligence in wartime, censorship, subterfuge, the significance of Churchill in the Dardanelles campaign, the Zimmermann telegram, the USA's entry to the First World War in 1917, and more.

With supporting text and images by Philip Vickers, this is a unique insight into the thinking of one of Britain's pioneering intelligence leaders.