Secrets and spies

1 Bletchley Park, the Buckinghamshire mansion that housed Britain’s Government Code and Cypher School

2 Ronald Seth was a British spy who became a German double agent

3 Harro Schulze-Boysen, a Luftwaffe officer and member of the ‘Red Orchestra’, fed information to the Soviets

4 Noted historian Hugh Trevor-Roper monitored the German Abwehr for MI6

5 Smoke belches from a vessel torpedoed by a U-boat. Deciphering German messages helped stem attacks

6 Bill Tutte, whose work at Bletchley Park was pivotal in understanding and breaking the Lorenz encryption system

7 The Lorenz Schlüsselzusatz (SZ) was Germany’s most powerful cipher machine

8 A member of the Women’s Royal Naval Service operates a Colossus computer at Bletchley Park in 1943

9 Soviet superspy Richard Sorge, who infiltrated the German embassy in Tokyo