This chapter begins to shape the theory of authority posited by this book, by exploring the way in which the authority of international criminal law is rooted in both justice and rights, exploring the development of international criminal justice in parallel with the human rights movement, and the way in which both have sought to serve victims of abuse. It also explores the way in which a reliance on State consent as the source of authority can undermine the authority of international criminal law. This argument is underpinned using Third World Approaches to International Law (TWAIL) scholarship, which offers the opportunity to move away from the Euro- and State-centric approach to international criminal law and encourages a greater focus on domestic prosecution. The discussion engages with what this complete approach should comprise, exploring the impact of generalised support for domestic prosecutions to ensure that its exercises of power are truly legitimate.