The Solidarity movement of the early 1980s not only triggered a transformation in Polish society, it forced a fundamental reconsideration of the nature of socialism throughout the Soviet Union and Eastern Europe. Seen as one of the most important social movements of the century, Michael Kennedy develops a theoretical conception of Soviet-type societies by analyzing Solidarity's significance. He explains the background to the nature of the conflict between Solidarity and the authorities and considers the implications of Solidarity's struggle for the theory of the Soviet-type system's reproduction and transformation. Then, the internal constitution of Solidarity in terms of gender and, in particular, cross-class alliances is examined, which is followed by the implications of his analysis both for understanding perestroika in the Soviet Union and more generally for reformulating a critical sociology of Soviet-type societies. As Soviet-type societies are in translation, there is a pressing need for theoretical reconceptualization. This pathbreaking study will become essential reading for specialists and students of Soviet and East European Studies, and of modern Poland in particular; specialists in political sociology and the sociology of social movements and for activists in radical politics.