It was a historical turning point for the wave of revolutions that swept the Eastern Bloc, starting in Poland that summer with the beginning of a move towards private enterprise, coming to a head with opening of the Berlin Wall in November, embracing the overthrow of the communist dictatorship in Romania in December and ending in December 1991 with the dissolution of the Soviet Union. Collectively known as the Revolutions of 1989, they heralded the beginning of the post–Cold War period.