Information about Auschwitz became available to the Allies as a result of reports by Captain Witold Pilecki of the Polish Home Army who, as “Tomasz Serafiński” (serial number 4859), allowed himself to be arrested in Warsaw and taken to Auschwitz. He was imprisoned there from 22 September 1940 until his escape on 27 April 1943. Michael Fleming writes that Pilecki was instructed to sustain morale, organize food, clothing and resistance, prepare to take over the camp if possible, and smuggle information out to the Polish military. Pilecki called his resistance movement Związek Organizacji Wojskowej (ZOW, “Union of Military Organization”).