Introduction: trends towards particularism in European citizenship policies

In this introduction to the special issue, we present the general lines of particularistic tendencies in citizenship policies in Europe. Norms that establish special treatments for specific groups of people are increasingly important in the citizenship laws of European countries, but remain understudied in literature. We summarize the development of comparative citizenship legislation research in Europe and the social relevance of formal citizenship in contemporary societies, in order to contextualize the significance of particularistic tendencies in this field. We further underline how different definitions of 'Europe' (European Union, Council of Europe, Schengen Area, specific regional groupings of countries) are relevant for the study of citizenship legislation. Finally, we introduce the articles of the special issue.