Jan Karski

Karski was his nom de guerre; he had been born Jan Kozielewski, the youngest of eight children, in Lodz, Poland's second-largest city, on April 24, 1914. Karski was a liaison officer of the Polish underground, who infiltrated both the Warsaw Ghetto and a German concentration camp and then carried the first eyewitness accounts of the Holocaust to a mostly disbelieving Anthony Eden and Franklin Roosevelt.