Territory has always played a key role in the origins, conduct, and consequences of armed conflict. For territories to exist in any meaningful sense, human groups need to think of them in the first place, and then act upon these thoughts: territory is what states and societies make of it. In Shifting Grounds, Burak Kadercan draws upon a wide variety of cases, ranging from the Thirty Years War to ISIS, to examine the relationship between "territorial ideas" and armed conflict. He argues that states and societies have adhered to different forms of territoriality across time and space, and territory, as well as territorial control, has meant different things in different time periods and regions. Building on this premise, Kadercan makes two claims. First, how state elites conceive territory within and beyond their domains affects their military objectives as well as methods and strategies for waging war. Second, adherence to different forms of territoriality leads to different modes and patterns of war, and wars themselves may affect how state elites and societies conceive territories. Kadercan then turns to the transformative roles that wars can play in shaping dominant territorial ideas and geopolitical assumptions and how the impact of such wars differs in Western and non-Western regions. Ranging broadly across different eras and world regions, Shifting Grounds sheds light on the shifting nature of the relationship between territorial ideas and armed conflict not only in the context of the distant the past, but also in present-day global politics.