Short answers, pulled from the story.
Józef Piłsudski was a Polish statesman who served as Chief of State from 1918 to 1922 and became the first Marshal of Poland in 1920. He is regarded as the father of the Second Polish Republic, which was re-established in 1918 after 123 years of partition, and remained the de facto leader of Poland from 1926 until his death in 1935.
The Battle of Warsaw in August 1920 was a decisive Polish victory that halted the Soviet westward advance during the Polish-Soviet War. Piłsudski devised the battle plan, which concentrated a roughly 20,000-man Reserve Army to strike through a gap between Soviet fronts; the plan was dismissed as a ruse by Soviet commander Mikhail Tukhachevsky, contributing to the Soviet defeat.
Piłsudski was arrested on the 22nd of March 1887 by Tsarist authorities on charges of plotting with Vilnius socialists to assassinate Tsar Alexander III. His main connection to the plot was through his brother Bronisław. He was sentenced to five years of exile in Siberia, first at Kirensk on the Lena River, then at Tunka.
The May Coup took place from the 12th to the 14th of May 1926, when Piłsudski returned to power with the support of the Polish Socialist Party, Liberation, the Peasant Party, and the Communist Party of Poland. Piłsudski had hoped for a bloodless takeover, but the government refused to surrender; 215 soldiers and 164 civilians were killed, and over 900 were wounded.
Piłsudski died of liver cancer on the 12th of May 1935 at Warsaw's Belweder Palace, after several years of declining health that had been kept from the public. His body is interred in the Crypt under the Silver Bells in Kraków's Wawel Cathedral; his heart was buried in his mother's grave at the Rasos Cemetery in Vilnius, and his brain was willed for study to Stefan Batory University.
Piłsudski replaced the National Democrats' ethnic-assimilation policy with a "state-assimilation" approach under which citizens were judged by loyalty to the state rather than ethnicity. He was widely recognized for opposing antisemitic policies, and many Polish Jews viewed him as a guarantor of stability; his death in 1935 was followed by a deterioration in the quality of life for Poland's Jewish population.