The Responsibility to Protect (R2P) clearly has normative properties, however its precise normative status is more in dispute. As an extended introduction to the volume, this chapter provides an overview of the history and trajectory of the R2P. It then focuses on how existing academic literature has sought to understand the R2P. Finally, it provides the theoretical framework of the volume by framing R2P both within current understandings of norms in international relations’ constructivist thought and how it may interact with other normative agendas and regimes.