Over the few past centuries, and the last 65 years in particular, there has been a tremendous reduction in global linguistic diversity, as people abandon minority language varieties and switch to larger and what they perceive to be more economically, socially and politically powerful regional or national languages. In addition, governments have been promoting standardised official languages for use in schooling, media and bureaucracy, often under a rubric of linguistic unity supporting national unity. The last two decades have seen a significant increase in interest in minority languages and language shift, endangerment and loss, in academia and among language speakers and the wider public. There has also been growing interest from anthropological linguists and sociolinguists in the study of language ideologies and beliefs about languages.This volume brings together chapters on theoretical and practical issues in these two areas, especially the views of linguists and communities about support and revitalisation of endangered languages. The chapters thus go straight to the heart of ideological bases of reactions to language endangerment among those most closely involved, drawing their discussions from case studies of how language ideologies and beliefs affect language practices (and vice versa). Most of the authors conduct collaborative community-based research and take a reflective engagement stance to investigate (potential) clashes in ideological perspectives. This is one of the key theoretical and practical issues in research on endangered languages, and has important implications for language documentation, support and revitalisation, as well as language policy at local, national and international levels.