Janusz Korczak (1878-1942)

Janusz Korczak, the pen name of Henryk Goldszmit, was a Polish-Jewish educator, children's author, and pediatrician known as Pan Doktor ("Mr. Doctor") or Stary Doktor ("Old Doctor"). After spending many years working as director of an orphanage in Warsaw, he refused freedom and stayed with his orphans when the institution was sent from the Ghetto to the Treblinka extermination camp, during the Grossaktion Warsaw of 1942.

Biography https://en.wikipedia.org/wiki/Janusz_Korczak