Linguistic boundary of Brittany between Celtic-speaking (west) and Romance-speaking (east) Brittany. A language border or language boundary is the line separating two language areas. The term is generally meant to imply a lack of mutual intelligibility between the two languages.

Map showing native languages of Europe. Striped areas indicate several mother tongues in the region. For example, Brussels is a majority-French city, shown striped French and Dutch because of the Dutch minority residing there. All political borders shown are de jure. In areas where data was difficult to gather estimates have been made. Source ...

debates over cultural identity in European borderlands. This article explores the nationalist and regionalist motivations behind linguistic map making along the French-German border, one of the most disputed in modern European history. KEYWORDS: Borders, unofficial borders, language, linguistic boundaries, national identity, regional

The cartographic techniques that Europeans invented to map their language borders involved a combination of linguistic surveys, on-site observations and collaboration with locals. Once printed, language maps found a broad public audience and helped to structure debates over cultural identity in European borderlands.