The Warsaw Security Pact, more formally the Treaty of Friendship, Cooperation and Mutual Assistance, was entered into on May 14, 1955. It solidified the Soviet Union’s control over its Eastern European satellite states, specifically Albania, Bulgaria, Czechoslovakia, the German Democratic Republic (East Germany), Hungary, Poland, and Romania. In the years that followed, the Soviets and these satellites were referred to collectively as the Warsaw Pact—an alliance that lasted until the collapse of Communism in the Warsaw Pact states in the late 1980s and early 1990s.