This chapter seeks to introduce you to international law. Although it is introductory, some of the concepts remain contentious even now, and not everyone would agree with the views expressed here. This is important because it should be immediately clear to you that international law is not a static object of study. Indeed, its very 'legal quality' remains a matter of debate, while the continuing changes in international law give the subject a unique fluidity. Nevertheless, the core of this chapter supports the view that international law really is 'legal' and that it is important that this perspective is understood.