This chapter discusses early records of territory and boundary making; territory, boundaries, and frontiers; territory and the State; territory and Others; title to territory; the changing character of boundaries and frontiers; dominion over the sea and its seaward limits; appropriation and division of airspace; and spaces beyond State territory. It notes that Westphalian territoriality is still alive today. Territoriality is broadly respected today for all States, whereas in the past, only a handful of Western powers enjoyed full territorial sovereignty. For the last roughly 500 years, a bordered territory has been considered a suitable framework to organize governance over people. However, in recent years, there have been increasing signs that the traditional and rather categorical symbiosis between territory and power may no longer lay a legitimate claim to exclusivity.