This book proposes a multidisciplinary assessment of the impact of complex diversity on language politics and policies, analysing how the legacies of the old interact with the challenges of the new. Its main focus is on the interplay of multilingualism on the one hand, and the dynamics of transnationalism, globalisation, and Europeanisation on the other. This interplay confronts contemporary societies with unprecedented questions, as they face the need to come to grips with increasingly varied and pervasive manifestations of linguistic and cultural diversity. This volume offers an integrative approach that identifies the key social and political dimensions at hand, offering an innovative contribution to the ongoing conversation on the manifestations and management of multilingualism.