Listening devices were concealed in walls, light fittings, window ledges, and outside in plant pots and on benches.
Meanwhile, hidden away in basement rooms, the “Secret Listeners” transcribed and translated conversations that went on to aid several significant breakthroughs for the Allies.
Some 3,000 conversations were secretly recorded at Trent Park – but that was not the only tactic used to gather intelligence.
Inside the museum at Trent Park[Missing Credit]
The grandfather of popular British actress and writer Helen Lederer acted as a “stool pigeon”, befriending captives and joining in their conversations to pick up snippets of intelligence.
Ernst Lederer and his family left Czechoslovakia and came to England in 1939, when he was recruited by the Intelligence Corps and posted to Trent Park.
He mingled with the German generals to manipulate their conversations and tease out information.
The museum website says that his “affable personality” came in useful when extracting information and he was also asked to assess the captives’ characters and work out where they fitted into the Nazi hierarchy.
It adds: “This not only gave an indication of attitudes towards Hitler but also crucial information on weapons, tactics, and vital evidence into the Holocaust.”
Helen, who has appeared in Absolutely Fabulous and French and Saunders, said: “The fact that my grandfather was a secret listener was a secret he took to the grave.
“It means so much that this chapter of little-known history can be told through the museum.
“To imagine what the secret listeners may have felt as they listened to the captive generals upstairs is as important as it is humbling.”
Helen Lederer (centre, in black) at a museum launch event[Missing Credit]
Information relating to the German “Enigma” cipher machines was also recorded and passed on to the codebreakers at Bletchley Park.
In another instance, two Luftwaffe bomber pilots revealed the system used by Germany to accurately target British munitions factories.
One loose-lipped general accidentally alerted British intelligence to the development of German ballistic missiles.
Trent Park is the former residence of Sir Philip Sassoon, one of the wealthiest men in England at the time. He inherited it in 1912 from his father, Sir Edward Sassoon.
Philip Sassoon was a close friend of war-time leader Winston Churchill and served as an MP and as Under-Secretary of State for Air.
The bachelor would entertain political friends, members of the Royal Family, and artists such as Charlie Chaplin and Fred Astaire at weekends.
Sassoon died of the flu in 1939 and the house was requisitioned by the government as a centre for intelligence operations.
Dr Giuseppe Albano, Director of Trent Park House of Secrets, said: "Most people will come to Trent Park to discover the covert intelligence operation that took place here during the Second World War.
"What I hope will surprise them is that there is so much more to discover.
"Before the war, these rooms played host to conversations between politicians, royalty, writers and artists at a moment when Europe stood on the brink of conflict.
"We have taken great care to reveal the full significance of the house, weaving together stories from some of the most colourful and turbulent years of 20th-century British history.”
After the war, the house became a teacher training college, and eventually part of Middlesex University until 2012.
