The expansion of capitalism produces contests over the definition and control of resources. On a global scale, new patterns of resource exploration, extraction, and commodification create new territories. This takes place within a dynamic of frontiers and territorialization. Frontier dynamics dissolve existing social orders—property systems, political jurisdictions, rights, and social contracts—whereas territorialization is shorthand for all the dynamics that establish them and re-order space anew. Frontier moments offer new opportunities, and old social contracts give way to struggles over new ones. As new types of resource commodification emerge, institutional orders are sometimes undermined or erased, and sometimes reinterpreted, reinvented, and recycled. New property regimes, new forms of authority, and the attendant struggles for legitimacy over the ability to define proper uses and users follow frontier moments. The drawing of borders and the creation of orders around new resources profoundly rework patterns of authority and institutional architectures. We argue that the territorialization of resource control is a set of processes that precedes legitimacy and authority, fundamentally challenging and replacing existing patterns of spatial control, authority, and institutional orders. It is dynamics of this sort that the articles in this collection explore: the outcomes produced in the frontier space, the kinds of authority that emerge through control over space and the people in it, and the battles for legitimacy that this entails. This collection explores the emergence of frontier spaces, arguing that these are transitional, liminal spaces in which existing regimes of resource control are suspended, making way for new ones.