Social movements in Eastern Europe have a long history. Despite problems with defining the region, most scholars tend to locate it in the postsocialist countries of Europe, which re-gained independence after the fall of the Iron Curtain. One of the most significant movements in the world during this period was Solidarność, which emerged in Poland in 1980. Solidarność developed from a trade union and reportedly had 9–10 million members (approximately 25% of the population). In the Fall of Nations in 1989/1990 hundreds of thousands of people went into the streets protesting against the communist regimes, and this contributed to the collapse of the Iron Curtain. A large variety of movements evolved from that time, with some becoming quite vibrant. Although there are important differences among the countries in Eastern Europe that shape social movements, some parts of the movements’ histories and characteristics are common. These differences and commonalities, crucial for the composition of the movements and their repertoires of action, are a result of the movements’ histories, legal systems, and political situations.