This paper presents an overview of the theories and empirical knowledge we have acquired over the last 50 years on ethnoregionalist (ERP) family, since the publication of Lipset and Rokkan’s 1967 seminal article on cleavage structures, party systems, and voter alignments. While the rise of ethnic, regionalist or autonomist parties has become a permanent feature of party systems around the world, in this chapter we focus on the most pressing concerns regarding the state of this party family in Europe. Not only does Europe shows the longest historical trajectory of party mobilization in three different cycles of mobilization, but European integration has also created a new multilevel political system for shaping party ideologies, strategies and political opportunity structures for advancing political demands. In this paper we seek to update the current state of the art of comparative research on ERPs family and explain the political dilemmas they in the European context. First, we synthesize the main issues regarding the conceptualization and labelling of the party family as well as the current state of the art. Second, we present the performance of ERPs and the electoral, office and policy success of the party family (in terms of electoral success at the regional, national and European level, government participation and policy performance) and the determinants of their success. ERPs also gained scientific relevance as they remind us of the prominence historic Rokkanite cleavages, and their capacity to (re-)emerge and re-align party systems while competing with new competitors situated on the GAL-TAN divide. Also, as they often operate at the regional, national and European level, they illustrate the dynamics of multilevel party politics and inter-institutional bargaining. Third, we examine the Europeanisation of the party family and provide evidence on the position of the party family regarding European integration and its change and continuity over time. We conclude by exploring the extent to which the last decade has brought up a fundamental transformation or a consolidation of the opportunities and threats of this party family and evaluate the strengths and weaknesses of their comparative analyses in theoretical and methodological terms.