IN 1939, a quiet brick mansion in the Buckinghamshire countryside called Bletchley Park became the unlikely headquarters for one of the most important and secretive decoding efforts of all time – the attempt to break the Nazi’s coded messages sent by the regime’s infamous Enigma machines.

These ingenious electronic devices performed a triple scramble on messages typed into the machine, with all machines reset daily to encrypt messages in a fresh way. At the height of the war in 1945, more than 9,500 people worked in three shifts around the clock at Bletchley Park – which became known as Station X (X for 10, as it was the 10th such wireless snooping station set up in the UK). Most of the workers were women.

To crack the code, two machines were used – an electronic “bombe”, which helped to find likely settings for the day’s Enigma messages – and eventually, the room-sized Colossus, considered by many to be the first digital computer.

Much work was done tediously by hand. Bletchley became the workplace of an odd mix of mathematicians, physicists, chess players, actors and military men and women, including many WRNs (members of the Women’s Royal Naval Service). Locals, unaware of Bletchley’s role but encountering many of its workers, referred to it as “the funny farm”.

Workers were recruited by being able to solve the Daily Telegraph cryptic crossword in under 12 minutes. Bletchley’s most famous resident was probably the brilliant but troubled mathematician Alan Turing. Another was James Bond author Ian Fleming, a role he never could reveal during his lifetime but which informed his novels.

The success of Bletchley’s codebreakers in cracking the Enigma code and others is attributed by historians to shortening the war by two years, saving countless lives. But for three decades, Bletchley’s role in the war remained top secret, classified information.

Even after it was disclosed, this important site was nearly destroyed 10 years ago, with plans to build a supermarket and housing estate. The efforts of a small group, including some Bletchley veterans, succeeded in getting the buildings listed and a museum established.

Bletchley Park’s funding remains precarious, though, with many second World War buildings still derelict. “Financially, we are on a bit of a knife edge, to say the least,” says Kelsey Griffin, director of museum operations.

KARLIN LILLINGTON