ABSTRACT
This dissertation entitled "An Appraisal of the Development of Legal Foundation on the Concept of Crimes against Humanity in International Law" aimed at examining the various constitutive legal instruments on the field of crimes against humanity in international law vis-à-vis the obligation of states to take practical measures to endure respect for the performance of such obligations under the various constitutive legal instruments. However, the justification for this research is that despite the fact that the term "crimes against humanity" has acquired enormous resonance in the legal and moral imaginations of the post-World War II which suggested that crimes against humanity are offences that aggrieved not only the victims and their own communities, but all human beings regardless of the community because such violate the very essence of the existence of humanity. Yet while the law limped lamely, the crime against humanity flourishes as if there is no law in existence, particularly of recent where there is an increase in violence at both local and international levels. For example, according to some estimates, nearly 170 million civilians have been subjected to genocide, war crimes and Crimes Against Humanity in the 21st century. In view of these events therefore the objective of this research is to identify the factors responsible for the prevalence of such crimes and to proffer solutions to the lapses identified (if any). In conclusion, it is recommended (among others) that there is the need for a specific international treaty on crimes against humanity which will provide a comprehensive definition of crimes against humanity; and by so doing it will harmonized constitutive elements of each of the crimes against humanity and promote greater certainty and uniformity in the development of the jurisprudence of the law of crimes against humanity. The sources of information relied upon here are relevant text materials, international instruments, domestic instruments, judicial authorities and internet materials.