The relative stability of Polish society in the decades following World War II presents something of a puzzle. By 1970, that stability gave way to a series of crises that generated domestic and international instability for much of the following twenty years, during which Polish society was in a state of “permanent revolution,” deeply alienated from its government. From the opposition's perspective, this revolution was part of an ongoing struggle that Poles had waged since the end of the war against the ruling minority who supported the Soviet-backed Communist-dominated party-state. Eventually the Polish people, led by liberal and Catholic dissidents and labor activists, forged a revolutionary mass movement, Solidarity. Solidarity's struggle for human rights, the material well-being of the Polish people, and the sovereignty of Poland undermined the foundations of the party-state. In 1989, Solidarity freed Poles from Communist rule, setting the stage for the collapse of the Soviet empire in Eastern Europe and the liberation of the entire region.