This thesis presents some of the fundamental problems the discipline of international relations faces, using the example of the "Westphalian myth". The origin, beginning, development and sustainability of the narrative that has marked the discipline of international relations, the socalled "Peace of Westphalia" is being thematized and it is questioned whether this narrative is in fact a "Westphalian myth" and how, when, where and why it was created. Furthermore, through the discussion of the "Westphalian myth", the context of the development of the concept of the international order is analyzed by thematizing its most important principles and concepts in historical and political perspective. Showcases of the nature and the effects of the international order are presented also. It is demonstrated throughout the thesis that the "Peace of Westphalia" as well as the "Westphalian system" are not well grounded in history or in international political practice. A critique of the conclusions derived from this disciplinary myth has been laid out, particularly in the sense of which obstacles exist in the further thinking about, and taking part in the field of International Relations and the international politics