Practically almost all the basic matters that make up the political and social agenda of this decade are related to two basic categories: citizenship and multiculturalism. The way in which the connection between these two basic pillars is managed constitutes the principal factor in the social, political and cultural transformation of our epoch. This work has two aims: on one hand, and in relation to the general subject of this monograph it is argued that the question of immigration is part (...) of a wider dynamic of discussions on the basic foundations of our modern era, resulting from the double process of State-building and Nation-building; on the other hand it underlines that the first victim of this process of contextual change is precisly the product of this double historical movement: the traditional notion of citizenship, which has difficulties in finding resources to administer the new phenomena tied to multiculturalism. In this framework, we propose the basic question: in what sense does multiculturalism pose problems to the tradition of citizenship? We start from the following situation: what happens when the traditional notion of citizenship is used in multicultural contexts? I structure my argumentation in five sections. In the first section, I set out the conceptual framework within which present-day arguments are situated, composed of three basic elements: the State, the Nation and Citizenship. In the second section, we enter into the discussion on the traditional concept of citizenship, focusing on its normative and empirical basis from a comparative perspective. In the third section, we are concerned with the concept of multiculturalism. In the fourth section I deal with what I have called the contexts of multiculturalism., that is, the different dimensions that call into question the indivisible (and sacred) character of the State, the Nation and Citizenship. We introduce, in succesion, the pluralism of cultural identities, the pluralism of national identities, immigration, the political construction of the European Union and, finally globalisation. In the fifth and last section we draw up a final balance giving a historical sense to our arguments. (shrink)