Rudolf Kastner (1906–1957), also known as Israel Rezső Kasztner, was born in Kolozsvár, Austria-Hungary. Kastner attended law school, then worked as a journalist for Új Kelet as a sports reporter and political commentator. He also became an assistant to Dr. József Fischer, a member of the Romanian parliament and leading member of the National Jewish Party, and in 1934, he married Fischer's daughter, Erzsébet.Kastner gained a reputation as a political fixer, and joined the Ihud party, later known as Mapai, a left-wing Zionist party. He also helped to set up the Aid and Rescue Committee, along with Joel and Hansi Brand, Samuel Springmann, Ottó Komoly, a Budapest engineer, Ernő Szilágyi from the Hashomer Hatzair, and several others.According to Joel Brand, the group helped 22,000–25,000 Jews in Nazi-occupied Europe reach the relative safety of Hungary between 1941 and March 1944, before the German invasion of that country on 19 March that year.