The structure and content of international law have been constantly changing from the early modern times to our days. In the course of the last hundred years, the number of sovereign actors quadrupled, and a far-reaching normative expansion increased the number of relevant subject matters and resulted in more thorough international regulations and several enforcement systems of varying efficiency. Since a major paradigm shift after World War II, the past few decades saw the waning exclusivity of the role of sovereigns in the international system, yet their dominance remains unquestionable.