One of the last surviving wartime codebreakers has died at 93.
Captain Raymond "Jerry" Roberts, who died on Tuesday following a short illness, was part of a team at Bletchley Park, in Buckinghamshire, which helped to crack the German Tunny system used by Hitler, Mussolini and other high ranking generals during the Second World War, a Bletchley Park spokeswoman said.
He was the last survivor of the nine cryptanalysts who worked on Tunny.
Capt Roberts joined Bletchley Park as a cryptographer and linguist in 1941 and was one of four founder members of the Testery, an elite unit named after the man leading it, Ralph Tester, which cracked the Tunny code - making it possible to read Hitler's messages during the war.
The Testery team, which grew to 118 by the end of the war, managed to reverse-engineer the Tunny, which had 12 encryption wheels to the Enigma machine's three, described by Bletchley Park as "an incredible feat of dedication".
The spokeswoman said: "Jerry came to Bletchley Park straight from university but they were all in unchartered territory. It was new ground for everybody."
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.
Capt Roberts worked at Bletchley Park until 1945 before moving to the War Crimes Investigation Unit for two years, followed by a 50-year career in marketing and research.
He was made an MBE in 2013 in recognition of his service to Bletchley Park and codebreaking, and in his later years campaigned for his colleagues to received due recognition for their work.
He was keen to see commendation for the "4T's" - the Testery as a whole, and three colleagues responsible for major discoveries - Alan Turing, who broke the naval Enigma; Bill Tutte, who broke the Tunny system to help shorten the war; and Tommy Flowers, who designed and built the Colossus, which sped up some stages of the breaking of Tunny traffic.
Speaking in 2012 after being told of his MBE, Capt Roberts, from Liphook, Hampshire, said: ''They did a brilliant job, we were breaking 90% of the German traffic through '41 to '45.
"We worked for three years on Tunny material and were breaking, at a conservative estimate, just under 64,000 top line messages.
"It was an exciting time because once you start getting a break on a message and seeing it through and getting it."
Capt Roberts, who was married to Mei, had seven children and stepchildren.
The Bletchley Park spokeswoman said: "In the last six years of his life he campaigned absolutely tirelessly for awareness and the achievements made at Bletchley Park.
"During the war, people in one room did not know what people were doing in the next room, never mind another department. It's still a jigsaw puzzle even now."
Describing Capt Roberts as "lovely" and "absolutely charming", she said: "He was passionate about what he and his colleagues achieved.
"He did not want to blow his own trumpet but to have the work of his colleagues recognised."