One of the most pressing issues in contemporary European societies is the need to promote integration and social inclusion in the context of rapidly increasing migration. A particular challenge confronting national governments is how to accommodate speakers of an ever-increasing number of languages within what in most cases are still perceived as monolingual indigenous populations. This has given rise to public debates in many countries on proposals to impose a requirement of competence in a ‘national’ language and culture as a condition for acquiring citizenship. These debates in turn have revealed an urgent need to develop a fuller conceptual and theoretical basis than is currently available for the widespread public discussion of the linguistic and cultural requirements being proposed as elements in the gate-keeping process leading to the achievement of citizenship in many EU member states. The controversial nature of such policy proposals and their potentially far-reaching consequences are often highlighted in public debates on social inclusion and integration. This however is frequently conducted almost entirely at a national level within each state, with little if any attention paid either to the broader European context or to comparable experience in other parts of the world. At the same time, further EU enlargement and the ongoing rise in the rate of migration into and across Europe suggest that the salience of these issues is likely to continue to grow. This volume focuses on these debates and seeks to problematise many existing definitions regarding language and citizenship and to challenge some of the assumptions underlying the new ‘testing regimes’.