Researchers crack MI9 codes to discover PoWs’ wartime requests

Mathematicians, historians and geographers have worked together to crack codes used by MI9 to conceal information going in and out of prisoner of war camps across Europe during the Second World War. They give a fascinating insight into how the Allies were trying to engineer escapes from the camps, but also show the PoWs were passing on vital military intelligence to their commanders back in London. It has also for the first time enabled the family of a former code writer to understand the secret messages he had hidden in his letters home during the war. Dr Harry Bennett, Associate Professor of History at the University, said: “Coded messages played a huge part in the war effort on both sides, as they were undoubtedly the best way to get messages or instructions through. The MI9 code was especially important, as their chief mission was to source equipment and supplies for prisoners of war who would then attempt to orchestrate an escape. But from these letters we now know they were also passing on information about key German sites, such as munitions dumps. The letters go to emphasise just how invaluable the code writers were to the Allied war effort.