The collapse of the warsaw pact, 1989-1990
Communism in Eastern Europe was swept away in the short period from August 1988 to December 1991,. Poland was the first to reject communism, closely followed by Hungary, East Germany and then Czechoslovakia. All the Eastern European satellites left the communist bloc eventually, the dissolution meant the collapse of the Warsaw Pact, the military alliance that the bloc had formed in 1955.