Jan Kowalewski

Lt. Col. Jan Kowalewski (23 October 1892 – 31 October 1965) was a Polish cryptologist, intelligence officer, engineer, journalist, military commander, and creator and first head of the Polish Cipher Bureau. He recruited a large staff of cryptologists who broke Soviet military codes and ciphers during the Polish-Soviet War, enabling Poland to weather the war and achieve victory in the 1920 Battle of Warsaw.