To establish a common framework for the individual chapters explaining the intricacies of governance theory, the Introduction first defines the concept of governance and then specifies the basic understanding of governance that informs the contributions to this Handbook. It then explores the rise and development of the governance debate in Western liberal democracies and other parts of the world. Having defined the concept of governance and explored its origins, the Introduction reflects on the content and purpose of theories of governance and the need for a Handbook dedicated to the study of governance theory. This need arises from the rapid expansion of empirical studies of governance, which prompts us to consolidate, assess and further develop the theoretical foundations of this field. At the end of the Introduction, the purpose and content of the four parts of the Handbook are explained and the different ways that it can be used are outlined.