The document summarizes the collapse of the Soviet Union in the late 1980s and early 1990s. It began with the formation of the Solidarity trade union in Poland in 1980 which received support from the Catholic Church and led to reforms. Mikhail Gorbachev came to power in 1985 and implemented reforms of glasnost, perestroika, and renouncing the Brezhnev Doctrine, but the reforms did not go far enough or fast enough. This led to demonstrations across Eastern Europe in 1989 and the fall of communist governments. The Berlin Wall was opened in November 1989, marking the collapse of Soviet control over Eastern Europe.