By . Chris Pleasance . The last remaining women code-breakers who operated Colossus - the world’s first computer - have been reunited after 70 years after a picture of them was published in a local paper. The women were all part of the Colossus C Watch at Bletchley Park in Buckinghamshire during the Second World War and were the world’s first computer operators. Most of them lost touch with each other after the war ended and they have not been together as a group for seven decades. This rare picture, taken at Bletchley where photography during wartime were strictly forbidden, shows the female code breakers. (Pictured: 1. Margaret Mortimer, 2. Margaret O-Connell, 3. Lorna Cockayne, 4. Margaret Kelly, 5. Joanna Chorley 6. Betty Warwick) Today: Six surviving women reunited after 70 years next to a replica of the Colossus machine which they operated . Their reunion happened after a rare picture of the Women’s Royal Naval Service was discovered in a drawer by veteran Joanna Chorley, 88, from Bucks. The photo, which was taken at the end of the Second World War, shows around 40 women dressed in smart berets and ties. It is believed to be one of only a handful in existence as photos were not meant to be taken at Bletchley Park during the war years. The huge Colossus computer was designed to break German ciphers used to encode messages between Hitler and the rest of his high command . Vital work: Women played a variety of roles from lowly clerks to operating machines and breaking into ciphers and codes . The women . spotted themselves in the photo after it was published in the national . papers to mark the 70th anniversary of Colossus. They . gathered together at Bletchley Park, where they were shown a . fully-functioning Colossus Mark II, which was rebuilt and unveiled in . 2007. Joanna . Chorley said: 'In war time you weren’t really meant to take photos so I . kept it very safe in my bureau, but I had forgotten all about it and . only found it when I was looking for something else. 'It was lovely to see everyone and be all together again after such a long time.’ It . was on 5 February 1944 that Colossus Mk I tackled its first . Lorenz-encrypted message, the highly sophisticated cipher used in . communications between Hitler and his generals during World War II. Margaret Mortimer, 87 was delighted to be reunited with members of the Women’s Royal Naval Service (Wrens). Most of them lost touch with each other after the war ended and they have not been together as a group for seven decades . Margaret O-Connell, 87, also featured in the photo which is believed to be one of only a handful in existence as photos were not meant to be taken at Bletchley Park during the war years . Lorna Cockayne, was also part of the group which were reunited after it was printed in a newspaper . Margaret Kelly, 87, from Monmouth, Wales, who joined the Wrens aged 18 . Joanna Chorley then and now. The reunion was organised after a rare picture of the Women’s Royal Naval Service was discovered in a drawer by Ms Chorley, 88, from Bucks . Betty Warwick, 89, worked at Bletchley Park as a registrar before going on to become a speech therapist after the war . Colossus was designed by British telephone engineer Tommy Flowers to speed up code-breaking of the complex Lorenz cipher. By the end of the war there were ten functioning Colossus machines and they had a decisive impact in shortening the war and saving countless lives. Colossus was the first electronic computer, but news of its existence was kept top secret for 30 years because of the sophistication and sensitivity surrounding the encryption it had helped to break. The computer was enormous, measuring 7ft high by 17ft wide and 11ft deep, weighing a tonne and using 8kW of power. It incorporated 2,500 valves, 501 of which are thyraton switches, about 100 logic gates and 10,000 resistors connected by 7 km of wiring. Back to reality: Of the 9,000 women who worked at Bletchley Park during World War II, just 600 went on to join the fledgling GCHQ or other branches of the secret services . Groundbreaking: But the work of female codebreakers wasn't always given the recognition it deserved at the time. Reading 5000 characters per second - faster than anything ever produced commercially ever since - it found the start wheel positions of Lorenz messages. It usually took Colossus up to three or four hours to establish the start wheel positions of messages, but it is often surmised that the Allies might have been reading some of the decrypted messages before they reached German High Command. By the end of the war, 63 million characters of high-grade German messages had been decrypted by the 550 people working on breaking Lorenz. In honour of the men and women who worked at Bletchley Park during the war, Tony Sale, co-founder of The National Museum of Computing, led a team to rebuild Colossus in 1994. On 15 November 2007, a rebuilt fully-functioning Colossus Mark II was unveiled to the public at The National Museum of Computing. The women were part of the Colossus C watch at Bletchley Park (pictured) in Buckinghamshire during the Second World War . The . intelligence war waging in a quiet corner of Buckinghamshire was to be . decisive in the Allied effort to win the Second World War. Station . X - known now as Bletchley Park - was the hub of Britain's code-backing . effort, where hugely talented mathematicians and inventors worked . tirelessly to give the armed forces a crucial helping-hand. Cambridge-educated mathematical genius Alan Turing . As . Winston Churchill himself made clear, the accurate information which . flowed from Bletchley Park every day, at a rate which sometimes reached . 6,000 messages a day, saved lives and gave Britain a crucial edge in . battle. Alan Turing, the . Cambridge-educated mathematical genius, and Post Office Engineer Tommy . Flowers, are the two most celebrated figures whose innovations greatly . improved the Allied ability to decipher German messages. The . Enigma machine, which was on sale commercially in the 1920s, was . modified by the Germans to make it more secure. They trusted completely . that its codes were unbreakable, and used it for all manner of important . communications. However, it was . thwarted in part thanks to Alan Turing's 'Bombe' device, which was able . to speed up the code-breaking process immeasurably. Turing . based his invention on a Polish device, the 'Bomba', which was handed . over to Britain just weeks before Poland was invaded in 1939. It . was not able to decipher German codes automatically, but once analysts . had manually deciphered a few letters by picking out common words, such . as the names of German generals or short words such as 'to' and 'they', . the device could rapidly test hundreds of other possibilities to put . together a code. Over . 100 of the machines were built to aid the code-breaking effort, but they . were all destroyed when the war ended. A replica was built in 2008, and . can be seen at Bletchley Park, which is now a museum. The . quest to beat the German intelligence services also resulted in the . construction of the world's first proper computer - called Colossus. Developed . by Tommy Flowers from a network of thousands of electronic valves, the . device was able to crack the Lorenz Cipher, which the Nazi high command . used for messages deemed too sensitive for Engima transmission. The . Colossus Mark II, which was five times faster than the original, was . finished less than a week before the Normandy landings, and gave the . Allies another crucial edge in the last phase of the war.
Six women worked on the Colossus machine at Bletchley Park during WW2 .
Computer was responsible for breaking German codes used in messages .
Seventy years after they worked together, the women have reunited .
Rare picture taken at Bletchley brought the former colleagues together .
By . Chris Pleasance . The last remaining women code-breakers who operated Colossus - the world’s first computer - have been reunited after 70 years after a picture of them was published in a local paper. The women were all part of the Colossus C Watch at Bletchley Park in Buckinghamshire during the Second World War and were the world’s first computer operators. Most of them lost touch with each other after the war ended and they have not been together as a group for seven decades. This rare picture, taken at Bletchley where photography during wartime were strictly forbidden, shows the female code breakers. (Pictured: 1. Margaret Mortimer, 2. Margaret O-Connell, 3. Lorna Cockayne, 4. Margaret Kelly, 5. Joanna Chorley 6. Betty Warwick) Today: Six surviving women reunited after 70 years next to a replica of the Colossus machine which they operated . Their reunion happened after a rare picture of the Women’s Royal Naval Service was discovered in a drawer by veteran Joanna Chorley, 88, from Bucks. The photo, which was taken at the end of the Second World War, shows around 40 women dressed in smart berets and ties. It is believed to be one of only a handful in existence as photos were not meant to be taken at Bletchley Park during the war years. The huge Colossus computer was designed to break German ciphers used to encode messages between Hitler and the rest of his high command . Vital work: Women played a variety of roles from lowly clerks to operating machines and breaking into ciphers and codes . The women . spotted themselves in the photo after it was published in the national . papers to mark the 70th anniversary of Colossus. They . gathered together at Bletchley Park, where they were shown a . fully-functioning Colossus Mark II, which was rebuilt and unveiled in . 2007. Joanna . Chorley said: 'In war time you weren’t really meant to take photos so I . kept it very safe in my bureau, but I had forgotten all about it and . only found it when I was looking for something else. 'It was lovely to see everyone and be all together again after such a long time.’ It . was on 5 February 1944 that Colossus Mk I tackled its first . Lorenz-encrypted message, the highly sophisticated cipher used in . communications between Hitler and his generals during World War II. Margaret Mortimer, 87 was delighted to be reunited with members of the Women’s Royal Naval Service (Wrens). Most of them lost touch with each other after the war ended and they have not been together as a group for seven decades . Margaret O-Connell, 87, also featured in the photo which is believed to be one of only a handful in existence as photos were not meant to be taken at Bletchley Park during the war years . Lorna Cockayne, was also part of the group which were reunited after it was printed in a newspaper . Margaret Kelly, 87, from Monmouth, Wales, who joined the Wrens aged 18 . Joanna Chorley then and now. The reunion was organised after a rare picture of the Women’s Royal Naval Service was discovered in a drawer by Ms Chorley, 88, from Bucks . Betty Warwick, 89, worked at Bletchley Park as a registrar before going on to become a speech therapist after the war . Colossus was designed by British telephone engineer Tommy Flowers to speed up code-breaking of the complex Lorenz cipher. By the end of the war there were ten functioning Colossus machines and they had a decisive impact in shortening the war and saving countless lives. Colossus was the first electronic computer, but news of its existence was kept top secret for 30 years because of the sophistication and sensitivity surrounding the encryption it had helped to break. The computer was enormous, measuring 7ft high by 17ft wide and 11ft deep, weighing a tonne and using 8kW of power. It incorporated 2,500 valves, 501 of which are thyraton switches, about 100 logic gates and 10,000 resistors connected by 7 km of wiring. Back to reality: Of the 9,000 women who worked at Bletchley Park during World War II, just 600 went on to join the fledgling GCHQ or other branches of the secret services . Groundbreaking: But the work of female codebreakers wasn't always given the recognition it deserved at the time. Reading 5000 characters per second - faster than anything ever produced commercially ever since - it found the start wheel positions of Lorenz messages. It usually took Colossus up to three or four hours to establish the start wheel positions of messages, but it is often surmised that the Allies might have been reading some of the decrypted messages before they reached German High Command. By the end of the war, 63 million characters of high-grade German messages had been decrypted by the 550 people working on breaking Lorenz. In honour of the men and women who worked at Bletchley Park during the war, Tony Sale, co-founder of The National Museum of Computing, led a team to rebuild Colossus in 1994. On 15 November 2007, a rebuilt fully-functioning Colossus Mark II was unveiled to the public at The National Museum of Computing. The women were part of the Colossus C watch at Bletchley Park (pictured) in Buckinghamshire during the Second World War . The . intelligence war waging in a quiet corner of Buckinghamshire was to be . decisive in the Allied effort to win the Second World War. Station . X - known now as Bletchley Park - was the hub of Britain's code-backing . effort, where hugely talented mathematicians and inventors worked . tirelessly to give the armed forces a crucial helping-hand. Cambridge-educated mathematical genius Alan Turing . As . Winston Churchill himself made clear, the accurate information which . flowed from Bletchley Park every day, at a rate which sometimes reached . 6,000 messages a day, saved lives and gave Britain a crucial edge in . battle. Alan Turing, the . Cambridge-educated mathematical genius, and Post Office Engineer Tommy . Flowers, are the two most celebrated figures whose innovations greatly . improved the Allied ability to decipher German messages. The . Enigma machine, which was on sale commercially in the 1920s, was . modified by the Germans to make it more secure. They trusted completely . that its codes were unbreakable, and used it for all manner of important . communications. However, it was . thwarted in part thanks to Alan Turing's 'Bombe' device, which was able . to speed up the code-breaking process immeasurably. Turing . based his invention on a Polish device, the 'Bomba', which was handed . over to Britain just weeks before Poland was invaded in 1939. It . was not able to decipher German codes automatically, but once analysts . had manually deciphered a few letters by picking out common words, such . as the names of German generals or short words such as 'to' and 'they', . the device could rapidly test hundreds of other possibilities to put . together a code. Over . 100 of the machines were built to aid the code-breaking effort, but they . were all destroyed when the war ended. A replica was built in 2008, and . can be seen at Bletchley Park, which is now a museum. The . quest to beat the German intelligence services also resulted in the . construction of the world's first proper computer - called Colossus. Developed . by Tommy Flowers from a network of thousands of electronic valves, the . device was able to crack the Lorenz Cipher, which the Nazi high command . used for messages deemed too sensitive for Engima transmission. The . Colossus Mark II, which was five times faster than the original, was . finished less than a week before the Normandy landings, and gave the . Allies another crucial edge in the last phase of the war.
for seven decades. This rare picture, taken at Warwick) Today: Six surviving women reunited sophisticated cipher used in . communications be taken at Bletchley Park during the war years . speech therapist after the war . Colossus was messages. The . Enigma machine, which was on sale decipher German codes automatically, but once