This article contributes to the critical historical research that has demythologised the ‘noble origins’ of the International Relations discipline (IR) by exposing its imperial, colonial, and racist legacies. Where most critical historiographies have unveiled the centrality of racialised and imperialist ontologies in individual thinkers and theories, this article traces imperialist origins of international thought by reconstructing its impact on administrative-institutional infrastructures. Specifically, it interrogates the most systematic and institutionalised attempt to define the ‘subject matter’ of IR under the International Studies Conference (ISC) organised by the International Institute of Intellectual Cooperation (IIIC) of the League of Nations. Through a parallel reading of the archives from ISC's ‘administrative meetings’ and ‘study meetings’, the article contends that the seemingly academic discussions on the subject matter of IR in the ‘administrative meetings’ were in fact intertwined with the imperialist-colonial politics central to ‘study meetings’. The article thus not only challenges IR's conventional history, but its historical ontologies by revealing how race and empire were central to the constitution of its very subject matter and its early institutionalisation.