The history of international law has recently come to the forefront of legal debates. Defined as the field of study that examines the evolution of public international law investigating state practice, the development of given legal concepts and the life and work of its makers, the history of international law (HIL) or international legal history has attracted the growing attention of international lawyers and legal historians, as well as other interested audiences. Despite its flourishing, the history of international law is still in search of a proper methodology. Two cultures of writing history compete in its making: ‘historians’ histories’ and ‘jurists’ histories’. While legal historians are interested in the past for its own sake and put it in context, lawyers tend to be interested in the past for the light it throws on the present. Several questions arise in this context. Should one stick to intra-disciplinary approaches, or endorse a comprehensive and multi-disciplinary stance, enabling international lawyers and legal historians to work together in mapping the history of international law? This article has an exploratory character and aims to address these questions investigating the converging divergences of the two cultures of writing the histories of international law.