Raoul Wallenberg, a Swedish businessman assigned as a diplomat to Sweden's embassy in Budapest, led one of the most extensive and successful rescue efforts during the Holocaust. Supported by the American War Refugee Board (WRB) and the American Jewish Joint Distribution Committee, Wallenberg protected tens of thousands of Hungarian Jews, issuing documents testifying that the Jews were under the protection of neutral Sweden. Diplomats from other neutral countries also participated in 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 certificates of protection to many Jews in Budapest under the name of nations which neutral Spain represented. At liberation, more than 100,000 Jews remained in Budapest, mostly because of these rescue efforts.