Borders are an integral part of our everyday life. Political, social, virtual, intellectual, and cultural borders are hotly contested, both in international contexts around issues of migration, security, trade, or global education and within nations trying to deal with increased diversity and changing notions of national identity and culture. Geographical borders separate states, regions, and cities. They mark the breadth and depth of territorial organization while informal symbolic and social boundaries define values and norms for social, cultural, and religious life. All types of borders can be conceived as social constructs: they may refer to cultural and historical contexts, result from international treaties or political negotiations or reflect public debates on controversial topics. In our increasingly globalized world in which human mobility and the constant circulation of goods, objects, ideas, and practices are also an integral part of everyday life, the importance of border making and crossing is growing. Borders and cross-border regions function therefore as manifestations of social, political, economic, and cultural change.