Expanding now familiar debates about the impact of the ‘historical turn’ upon the field of international law, this article considers some of the different ways in which ‘turn to history’ scholars have confronted the methodological and theoretical tensions arising from the central, yet paradoxical role occupied by the sources doctrine in international law. We suggest that the anxiety over the sources of international law as the basic methodological precepts of the discipline, has been a catalysing element for a radical reengagement with the canon of international law, one with a significant impact on the field’s existing parameters and doctrinal limits. Within the three streams of scholarship we explore here, history has become a site of creative engagement for scholars in opening up the discipline to diverse ends, one in which a new doctrinal universe can be created, and new issues, sources, subjects and approaches can be explored. Yet, by opening up international law’s sources doctrine reactionary causes and unjust ends may equally well be the result. This account is an attempt at diversifying the narrative surrounding the causal relationship between history and the ongoing changes to the field of international law, along with the differential practices, techniques and epistemological foundations behind the history of international law as an evolving discipline, and of the different scholarly motivations of its specialists.