Raoul Wallenberg, a Swedish diplomat assigned to Sweden's embassy in Budapest, led one of the most extensive and successful rescue efforts during the Holocaust. He worked with the American War Refugee Board (WRB) and the World Jewish Congress to protect tens of thousands of Hungarian Jews from deportation to the Auschwitz-Birkenau killing center. Diplomats from other neutral countries also joined the rescue effort. Carl Lutz, a Swiss diplomat, issued certificates of emigration, placing nearly 50,000 Jews under Swiss protection. Italian businessman Giorgio Perlasca, posing as a Spanish diplomat, issued forged Spanish visas to Jews. At liberation, more than 100,000 Jews remained in Budapest, mostly because of these rescue efforts.
Source: U.S. Holocaust Memorial Museum