The Guardian: Irena Sendler

Social worker Irena Sendler saw the inhumane conditions of the Warsaw Ghetto and knew she had to help. Crossing the dangerous Nazi barricade daily, Irena brought food, medicine, immigration papers, and a path to freedom to thousands of Jewish residents. When whole families began to disappear, however, Irena went one step further: she hid their children to keep them alive. Using falsified passports and a network of nuns and Polish families, Irena smuggled Jewish children to safety, keeping meticulous records to ultimately reunite them with their parents. Tortured for her efforts, she never gave up a single name, ultimately saving 2,500 children and countless generations to come.