Stanisław Ignacy Witkiewicz, commonly known as "Witkacy", was a Polish poet, playwright, novelist, painter, photographer and philosopher. After hearing the news of the Soviet invasion of Poland on 17 September 1939, Witkacy committed suicide on 18 September by taking a drug overdose and trying to slit his wrists. He convinced his young lover Czesława to attempt suicide with him by consuming Luminal, but she survived. Source: Wikipedia.
Tadeusz Kościuszko. Polish general. He led the 1794 Kościuszko Uprising against Imperial Russia and the Kingdom of Prussia as Supreme Commander of the Polish National Armed Force. A national hero of Poland, Lithuania, the United States and Belarus.
Kazimierz Pulaski (1747-1779) The commander of the Bar Confederacy and defender of Jasna Gora against the Russians. He commanded a cavalry brigade in George Washington's army during the American War of Independence. He died of wounds inflicted at the Battle of Savannah
Marian Rejewski was a Polish mathematician and cryptologist who in 1932 solved the plugboard-equipped Enigma machine, the main cipher device used by Germany. The success of Rejewski and his colleagues Jerzy Różycki and Henryk Zygalski jump-started British reading of Enigma in World War II; the intelligence so gained, code-named "Ultra", contributed, perhaps decisively, to the defeat of Nazi Germany.