How did Polish code breakers help Britain and France before World War II?

In the years leading up to World War II, Polish cryptanalysts played a foundational role in cracking the German Enigma cipher. Led by mathematician Marian Rejewski, the Polish Cipher Bureau successfully deduced the internal wiring of the Enigma machine and developed a mechanical system known as the bomba to identify daily encryption keys.1234

As the threat of a German invasion grew, the Poles recognized that their work was vital to the Allied cause. In July 1939, just weeks before the outbreak of war, Polish officials provided British and French intelligence with Enigma replicas and blueprints for their bomba machines.34

This intelligence was instrumental for the British code-breaking efforts at Bletchley Park. By studying the Polish successes, Alan Turing and his colleagues were able to develop the Bombe, a more advanced electromechanical device that industrialized the decryption process. This collaboration formed the basis of the Ultra project, which provided the Allies with critical military intelligence throughout the war.234