This chapter introduces the rationale for mapping the nature of Nordic fascism. It clarifies the theoretical, methodological, and conceptual starting points that inform the book chapters and binds them together. Nordic fascism is here construed as a revolutionary branch of radical nationalism that encompasses a plethora of historical and contemporary manifestations in Sweden, Norway, Denmark, and Finland. The introduction chapter outlines how Nordic fascists typically share a mythical belief in the exceptional Nordicness and The North as an idealised past and a desired future. It offers a unique historical overview of fascism in the Nordic countries, a development unfolding not only with varied pace and intensity across localities but also through entanglements that transcend national boundaries. Entangled history is presented as a joint effort by the chapter contributors to capture how political ideas and actions develop across the Nordic countries. The chapters of this book are all based on original research and present new findings – fragments – of an entangled history of Nordic fascism.