More than 80 veterans who played a vital but secret role in the efforts to end the Second World War gathered to mark the 80th anniversary of the start of the conflict.
Scores of former staff were reunited at Bletchley Park on Sunday where they had helped crack German codes to unravel Nazi intelligence.
It marked 80 years since Adolf Hitler led Nazi German forces to begin an attack on Poland.
It was an attack that triggered the Second World War two days later.
Betty Webb, who joined the Auxiliary Territorial Service in 1941 - which was the women's branch of the British Army at the time - said it was "immensely important" for her to attend the reunion.
The 96-year-old worked in the estate's mansion and was involved in registering the signals - made up of figures and letters - which had come in.
Asked if she has a favourite memory of her four years at Bletchley, Ms Webb said: "No, it is all favourite.
"For me, it was all great because it was a mix of people that I wouldn't have found unless I'd gone to university. It was an education for me."
"People often ask me why I joined up, and of course the answer to that is that the whole country was involved and I felt the need to do something to help the war effort," she said.
Bletchley Park housed some of the world's most gifted minds during the war, including computer scientist Alan Turing.
Staff who worked in intelligence had to sign the Official Secrets Act and could not talk about their work for decades.
The intelligence gathered at Bletchley Park is credited with providing strategic information that was passing between the top-level commanders and is believed to have shortened the war by two years and helped to save millions of lives.
Arthur Maddocks, 97, from Oxford, was 22 when he worked as a wheel setter inside the mansion as part of a section known as the Testery. He was based at Bletchley from August 1944 to May 1945.
"The Germans had a particular cipher machine called Lorenz which was basically a teletype machine.
"Tt had 12 wheels - Colossus [a set of early computers] was used to eliminate the first five and then the remaining seven were tackled by Major Testers section," he said.
Chief executive of the Bletchley Park Trust Charity Iain Standen said: "As a dwindling population it's great to have so many of them [veterans] here.
"It's very important, they connect this place to what it was all about in the Second World War."