Tommy Flowers' Colossus celebrated by the Royal Mail

Stamp issued to remember the achievement of Tommy Flowers who designed first programmable digital computer.

Colossus: Tommy Flowers' is invention remembered Royal Mail

While the world remembers the genius of Alan Turing who is credited with leading the code-breaking activities at Bletchley Park, the work of others is less well known.

Tommy Flowers is the latest to receive the ultimate accolade handed to our national heroes - a postage stamp.

Flower's story is an inspiring one. The son of a bricklayer from London's East End, he managed to get an apprenticeship as a mechanical engineer in the Royal Arsenal in Woolwich. While working there he also took evening classes at the University of London and got a degree in electronic engineering.

In 1926 he joined the nascent telecommunications branch of the General Post Office before moving to work at a research station in Dollis Hill. He gradually became convinced that an electronic system could be devised for telephone exchanges which would be revolutionary. Then came war and as things do in wartime, everything speeded up enormously.

It was then that Flowers outline an idea that would become Colossus - the first programmable digital computer. This was created to speed up the code-breaking of Lorenz-encrypted messages between Hitler and his generals.

The Lorenz cipher was much more complex than Enigma and could take weeks to decipher by hand. By reducing code-breaking times to a matter of hours, Colossus enabled the Allies to learn of German war plans almost in real time.

In December 1943, Irene Dixon was 19 when she arrived at Bletchley and for the next 18 months she was a Colossus operator.

But she didn't talk about her role for more than 50 years, until 1995 when she went to visit the team rebuilding Colossus". "Tommy Flowers' invention was fantastic and I'm especially proud of him because he was an East Ender like me," she said.

Betty O'Connell, who worked alongside Dixon on Colossus Mk 1, said: "I think it's marvellous that Tommy Flowers is being acknowledged by Royal Mail. It is such a shame that his achievement has been overshadowed because of the secrecy around Colossus for so many decades."

Kenneth Flowers, son of Tommy Flowers, also greeted the news warmly: "My father would be delighted with the recognition of Colossus on a first class stamp. I also know that he would have made it very clear that Colossus was a team effort and that he would have regarded the stamp as recognition of the team's work."

You can read more about Flowers here and about BT and Flowers here and about Colossus here.