The notion of jus cogens in international law encompasses the notion of peremptory norms in
international law. In this regard, a view has been formed that certain overriding principles of
international law exist which form “a body of jus cogens.” These principles are those from which it is accepted that no State may derogate by way of treaty. As a result they are generally interpreted as restricting the freedom of States to contract while ‘voiding’ treaties whose object conflicts with norms which have been identified as peremptory. However, both the scope and in fact very existence of this concept has been debated within the international legal community for many years. Consensus was finally reached as to a definition during the Vienna Conference held in 1969 (“the Vienna Conference”) and this was codified in Article 53 of the Vienna Convention on the Law of Treaties 1969 (“the Vienna Convention”).