Marian Rejewski, codebreaker who cracked Enigma

How much longer would WWII have lasted, how many more lives would have been lost if Marian Rejewski and his team had not cracked the Enigma code in December 1932? Although it is impossible to give a precise answer, many historians point out that without his achievements it would have been much more difficult for the Allies to decipher German dispatches during WWII.

Mr Rejewski was a Polish mathematician and cryptologist born in 1905 in Bydgoszcz (then Bromberg, the German Empire). He graduated from Poznań University in 1929. During his time at college, he began the secret cryptology course for German-speaking mathematics students organised by the Polish Army. Its main purpose was to break modern German cipher machines by using mathematical methods, mainly combinatorics and probability.

After completing the course, Marian Rajewski became a part of the decoding team, along with Henryk Zygalski and Jerzy Różycki. In December 1932, Rajewski solved the mystery of the German cipher machine Enigma, and demonstrated how it worked in practice in January 1933. With his team, he constructed the so called “cryptologic bomb” - an electromechanical device that enabled the German dispatches to be decoded.

Just five weeks before the outbreak of WWII, a replica of the Enigma machine, as well as the decoding method were presented by Marian Rejewski to representatives of British and French military intelligence. After the German aggression on Poland, he and his team were evacuated to Romania, then they got to France where they continued working on deciphering German messages.

The fall of France in 1940 resulted in the evacuation of the decoding team to Algiers. In September 1940, the cryptologists returned to southern France controlled by the Vichy government to work in an underground listening centre codenamed Cadix.

However, when the Germans entered southern France in November 1942, Rejewski and Zygalski (Różycki died in January 1942 when the ship he was travelling on from Algiers sunk in the Mediterranean) managed to get to Spain, but they were arrested by the Spanish police at a border crossing in the Pyrenees. Thanks to the intervention of the Polish Red Cross, they were released and sent to Madrid. From there, the cryptologists escaped to Portugal, from where they sailed to Gibraltar, and on July 3, 1943, finally reached Great Britain and joined the Polish Army shortly after.

Marian Rejewski continued cryptology and intelligence work together with Zygalski in the radio unit of the Commander-in-Chief of the Polish Armed Forces in Stanmore-Boxmoor near London, working on decrypting less complex German ciphers.

After the war ended, Rejewski returned to Poland where he worked as a civil servant in several Bydgoszcz factories. It wasn't until 1967 that he disclosed his involvement in breaking the Enigma cipher and wrote the memoirs he deposited at the then Military Historical Institute.

February 13, 2020 marks the 40th anniversary of Marian Rejewski’s death. He was laid to rest at the Powązki Military Cemetery in Warsaw.

The cryptologic achievements of Rejewski, Różycki and Zygalski and their contribution to the final defeat of Nazi Germany are unquestionable. Some historians state that their work may have shortened the war significantly.