The Diversification and expansion of International Law has sparked a series of debates on the present status and future of International Law; even more so, since the ILC decided to tackle the issue of fragmentation. One of the areas of research and controversy has been Article 31(3)(c) of the Vienna Convention on the Law of Treaties which, arguably, enshrines the principle of systemic integration. The aim of this article is to explore the evolution of Article 31(3)(c) from its first inception by the forefathers of international law up to the finalization of the text of the Vienna Convention on the Law of Treaties. By mapping the critical arguments in the three main fora of debate (i.e the Institut de Droit International, the International Law Commission and the Vienna Conference on the Law of treaties) what arises is a series of conclusions with respect to certain aspects of Article 31(3)(c) as well as certain recurring themes in the nature and progress of the discussions. All of the above will show that the drafting history of Article 31(3)(c) seems to suggest that the relevant provision was meant to serve a purpose expressed more concisely by the symbol of Ouroboros rather than of a mere "master-key" to the house of International Law.