The introductory chapter will help to understand the reasons why it is important to study federalism in Bosnia and Herzegovina.1 It will explain the background of this book and some of its evolutionary features. Furthermore, it will highlight the methodology used and define the major terms used in this study. The overall aim is to understand that Bosnia and Herzegovina as a federal country is studied as one case of a number of countries that demonstrate the evolution of new models of federalism, understood here as a political ideology and the normative basis of federation, which shall refer in this piece to a federal state.2 This conceptual distinction between federalism and federation informs the book throughout. Therefore, in particular the concluding remarks will refer to some comparative aspects of Bosnian federalism and federation. Finally, the introduction will discuss the structure of this study and the rationale behind it. In short, the book is structured so that the first chapter introduces the reader to the current debates on multinational federalism and multinational federations, whilst the following three chapters will analyse Bosnia and Herzegovina as an example of a new model of multinational federalism and federation. The aim of the concluding chapter is to widen the research findings and provide some insights into the wider comparative merit of this study.