The European labor movements developed in different directions during the twentieth century. The class formation literature has tried to explain these differences but left unexplored the internal dynamics of the labor movement and, above all, the differences in ideological schooling. Workers' education constitutes a forum for ideological schooling of members, and these educational settings can be identity constitutive and thus play an important part in the class formation process. In this article I analyze the institutions for workers' education in Sweden and Britain and I suggest that the variation of the design and practices of workers' education had an impact on the movements' developments in terms of identity formation and cohesiveness.The labor movement came to play a crucial role in the development of welfare states and democracy in the early twentieth century. Democratic citizenship was promoted by the reformist labor movement and became an important part of the consolidation of democracy during the interwar period. There were, however, significant differences between the European labor movements in terms of size, cohesiveness, ideology, and, ultimately, influence. In some of the Nordic countries, especially Sweden, the reformist labor movement became strong, unified, and influential. These countries developed comprehensive welfare states and peaceful industrial relations, while in other countries the labor movement was more fragmented. Different ideological factions ended up in conflict with each other instead of struggling together, making labor weak. Meanwhile in Spain, Italy, and Germany fascist movements overthrew democracy with support from parts of the working class. 2 How can we understand these national differences? There are varied explanations for the relative strength and ideology of the labor movements in Europe. The most common ones focus on structural variables and take the class formation literature as their point of departure. The internal dynamics of the labor movement and especially the differences in ideological schooling have, with few exceptions, not been the focus of comparative research on national labor movements. In this article I argue that examining workers' education may offer a path to a deeper understanding of the class formation process and, thus, a clearer grasp of national differences among labor movements. Workers' education constitutes a forum for ideological schooling of members that can be and has been identity-constitutive.To understand how class formation took place in different countries, we need to include workers' education in the analysis. In this article I analyze