This article examines the major milestones in the development of the notion of Responsibility to Protect in cases of genocide, war crimes, ethnic cleansing and crimes against humanity. In particular, the author examines the process that led to the adoption of this notion at the 2005 World Summit at the United Nations, its scope and the challenges and issues that may arise from its implementation. Finally, the paper presents some conclusions regarding the importance of the Responsibility to Protect in International Law.