Witold Pilecki, Polish officer and Resistance leader (b. 1901)
Witold Pilecki (13 May 1901 – 25 May 1948; Polish: [ˈvitɔlt piˈlɛt͡skʲi ] (listen); codenames Roman Jezierski, Tomasz Serafiński, Druh, Witold) was a Polish World War II cavalry officer, intelligence agent, and resistance leader.

As a youth, Pilecki joined Polish underground scouting, and in the aftermath of World War I, Polish militia and later, the Polish Army. He participated in the Polish-Soviet War which ended in 1921. In 1939 he participated in the unsuccessful defense of Poland against the German invasion and shortly afterward, joined the Polish resistance, co-founding the Secret Polish Army resistance movement. In 1940 Pilecki volunteered: 66  to allow himself to be captured by the occupying Germans in order to infiltrate the Auschwitz concentration camp. At Auschwitz he organized a resistance movement that eventually included hundreds of inmates, and he secretly drew up reports detailing German atrocities at the camp, which were smuggled out to Home Army headquarters and shared with the Western Allies. After escaping from Auschwitz, Pilecki fought in the Warsaw Uprising of August–October 1944. Following its suppression, he was interned in a German prisoner-of-war camp. After the communist takeover of Poland he remained loyal to the London-based Polish government-in-exile. In 1945 he returned to Poland to report to the government-in-exile on the situation in Poland. Before returning, Pilecki wrote Witold's Report about his Auschwitz experiences, anticipating that he might be killed by Poland's new communist authorities. In 1947 he was arrested by the secret police on charges of working for "foreign imperialism" and, after being subjected to torture and a show trial, was executed in 1948.His story, inconvenient to the Polish communist authorities, remained mostly unknown for several decades; one of the first accounts of Pilecki's mission to Auschwitz was given by Polish historian Józef Garliński, himself a former Auschwitz inmate who emigrated to Britain after the war, in Fighting Auschwitz: The Resistance Movement in the Concentration Camp (1975). Several monographs appeared in subsequent years, particularly after the fall of communism in Poland facilitated research into his life by Polish historians.