This review focuses on Pekka Hämäläinen's characterization and analysis of the Comanche empire as a spatial category in The Comanche Empire and discusses how this work relates to broader discussions about space and power in borderlands and imperial histories. Although empires have long been central actors in borderlands histories, “empire” has not necessarily been a category of spatial organization and analysis and certainly not one used to describe spaces controlled by Native peoples. By contrast, while Hämäläinen emphasizes the imperial characteristics of the economic, political, and cultural dimensions of Comanche history (as other contributors to this forum discuss), he also uses “empire” to characterize Comanche dominance spatially. Hämäläinen helps us to rethink the spatial dynamics that both shaped and were produced by the encounters between Comanches and Spaniards, French, Mexicans, Americans, and other Native peoples in the Great Plains during the eighteenth and nineteenth centuries. By analyzing how Comanches came to control vast stretches of the southern plains, The Comanche Empire challenges our assumptions about how Native polities and imperial powers (and groups like the Comanches that Hämäläinen argues were both) thought about territorial claims and how they employed more nuanced spatial strategies to assert their authority, extend their cultural influence, and control trade and resources.