In this introductory essay, we outline how recent events have generated considerable debate and discussion surrounding the future constitutional status of Scotland and the current devolutionary settlement in the UK, and how the aim of this collection of papers is to evaluate UK devolution and the policy mobilities surrounding it. We argue that there has been a tendency for scholars to concentrate on the detail of the constitutional and administrative structures and a reluctance to theorise devolution, and suggest geographers can offer a particular contribution here through an understanding of devolution as fundamentally about the interaction of politics, culture and territory. We discuss the value of considering the particular geographies of policy at work, and the role of the everyday work of civil servants in creating and sustaining the creation of new state spaces. We then briefly highlight the main findings of each of the papers in this special collection and show how, together, they add to our understanding of the geographies of devolution and of policy at a critical juncture in the devolution story. We conclude that whatever the particular future for the United Kingdom, the policy interactions between territories will continue to have an important role in their governance.