Diaspora and transnationalism have become popular concepts in academic as well as political discourses. Although originally referring to quite different phenomena, they increasingly overlap in today's usage. There is a conflation of meanings that goes hand in hand with a danger of reifying collective identities. The authors of this much-needed volume choose instead to analyse diaspora and transnationalism as research perspectives rather than as characteristics of particular social groups. The contributions focus on conceptual uses, theoretical challenges and methodological innovations in the study of social ties that transcend national and state boundaries. Bringing together scholars from a wide range of fields and approaches, this innovative volume demonstrates the need to cross disciplinary boundaries to fruitfully investigate border-crossing affiliations.