History shows that NGOs activity in the international arena has grown steadily since the beginning of the 20th century, accelerating its pace after the enactment of the UN Charter, which admitted pluralism not only between States, but also beyond States, because it acknowledged that individuals could interact with the United Nations not only through governmental organizations but also through non-governmental organizations. In NGOs: legitimate subjects of International Law, Eduardo Szazi presents a methodical appraisal of the role of NGOs in the contemporary world, addressing their main characteristics under each of the sources of international law, as well some pressing questions about the legitimacy deficit of States and Intergovernmental Organizations in the 21st centur