Prague underground was an underground culture developed in Prague, Czechoslovakia in the late 1960s and 1970s during the Czechoslovak normalization. The movement was characterized by resistance against conformity, conventions, and consumerism. Because of its non-conformity, it had serious problems with the communist regime which considered it as a political opposition. It was mainly expressed with experimental rock, art rock and psychedelic rock music (The Plastic People of the Universe, DG 307) and samizdat literature. Among the fans of this subculture was for example Czech ex-president Václav Havel.