The Customary International Law of Human Rights

Abstract

Customary international law is one of the principal sources of public international law. Unlike many branches of international law, human rights law did not first develop as custom and subsequently become codified. Human rights law was viewed as quintessentially a matter of sovereign concern to States until the mid-twentieth century, when treaties and declarations were adopted by the United Nations and other international bodies. Jurists only began to speak of human rights as customary law in the 1960s. Although its existence is uncontroversial, the content of customary international law in the area of human rights has not previously been analysed in a comprehensive manner. This book discusses the emergence of the customary law of human rights, the debates about how it is to be identified, and the efforts at formulation of customary norms. It examines human rights norms in order to determine whether they may be described as customary, using as a basis the content of the Universal Declaration of Human Rights. Much reliance is placed upon relatively new sources of evidence of the two elements for the identification of custom, namely State practice and opinio juris, in particular the increasingly universal ratification of major human rights treaties and the materials generated by the Universal Periodic Review mechanism of the Human Rights Council. The study concludes that a large number of human rights norms may be described as customary in nature, and that courts should make greater use of custom as a source of international law.