"The cracking of the “unbreakable” Enigma Code by analysts at Bletchley Park is believed to have tipped the balance of the war, by allowing the Allies to learn of German military plans. It was the initial work by [Polish Intelligence Officer] Colonel Langer’s team which paved the way for the British to unlock Enigma.
But for decades after the war, the role of Polish cipher experts went unrecognised. Canadian historian Witold K Liliental said Polish mathematicians broke the code before the outbreak of World War Two. Three young maths students took up posts as codebreakers in the Cipher Bureau of the Polish Army, under the command of Colonel Langer.
He said: “Realising the looming danger of impending war with Hitler, the Polish High Command decided to share the closely guarded secret with her Allies, Britain and France. This happened at a meeting in Warsaw in 1939.” He added: “For many years the role of Poles was either totally ignored or skimmed over with only vague references in historical literature.”" SOURCE
It's one of the saddest examples of selective history making: the Enigma Machine was captured, copied, and cracked by Polish Intelligence before the outbreak of the Second World War, as every Polish child knows, and Polish literature is rich in exploring the subject. Unfortunately, readers in the Anglo-American world, with access to only 2-3 % of books translated from other languages, will not have the opportunity to read the true account of breaking of the Enigma.