اصول قانونی‌بودن جرایم و مجازات‌ها در دادرسی‌های کیفری بین‌المللی

International criminal proceedings have been under serious criticism due to the absence of international lawmaker, courts with compulsory jurisdiction and organized sanctions which are the necessary requirements of a comprehensive and authoritative legal system. As during the Nuremberg and Tokyo trials, relying on justice could not fill the legality lacuna. Criticisms having been made during those trials and then, indicated that we should also take effort with regard to legality principles of crime and in the scope of International Criminal Law. The initial steps for the adoption and deployment of these principles have been slow but progressive. Analyzing international criminal proceedings in its basic form in Leipzig Court in the early twentieth century, the Nuremberg and Tokyo trials in the mid-twentieth century, ICTY and ICTR in the final decades of the twentieth century, as well as internationalized criminal courts, among which the special court of Sierra Leone at the end of the twentieth century, and finally ICC represents the deep and progressive evolutions and great distinctive orientations of international criminal justice system with regard to the acceptance and deployment of the principles of legality of crime and punishment. This article analyzes the process of evolution and the admission of principles on the development of international criminal law from the first generation of the courts to the International Criminal Court. This trend started with denial and failure to perform and ended in necessity and stipulation.