The major force behind the law was the All-German Bloc/League of Expellees and Deprived of Rights party, which had among its supporters - besides German citizens, who had fled or were expelled from formerly German territory annexed by Poland and the Soviet Union - many formerly non-citizens, who experienced by the end of World War II and the post-war years of ethnic cleansing, denaturalisation, robbing and humiliation (1945 until 1950) carried out by the governments of Czechoslovakia, Hungary, Poland, Romania, and Yugoslavia.