Janusz Korczak, the pen name of Henryk Goldszmit (22 July 1878 or 1879 – 7 August 1942), was a Polish Jewish educator, children's author and pedagogue known as Pan Doktor ("Mr. Doctor") or Stary Doktor ("Old Doctor"). After spending many years working as a principal of an orphanage in Warsaw, he refused sanctuary repeatedly and stayed with his orphans when the entire population of the institution was sent from the Ghetto to the Treblinka extermination camp by the Nazis, during the Grossaktion Warschau of 1942.