The literature on Indigenous language revitalization is dominated by sociolinguistic and normative approaches that focus on “the vitality of languages, the multiple facets of linguistic landscapes, and the effects of language policies on individuals and groups” (Sonntag and Cardinal, 2015: 6). Very little research, however, has been done using the tools of political science and public policy to analyze the emergence of language policies or the choices made by governments and organizations to protect, preserve and revitalize Indigenous languages. Using an historical institutionalist approach, this paper will examine the decline and revitalization of Manx Gaelic (Manx), the Indigenous language of the Isle of Man, a small island jurisdiction in the British Isles. Manx has been critically endangered for many decades, following its slow decline during the nineteenth and twentieth centuries, but in recent years has undergone a process of revitalization spearheaded by civil society organizations in partnership with government. The chapter identifies and discusses the reasons why Manx went into decline and the opportunities and challenges associated with promoting and sustaining its revitalization.