This article considers the relationship between the uses and forms of history within international law and questions of method in the development of histories of international law. It focuses on the advantages of genealogy as an approach to the history of international law given its capacity to both explain the way in which the law itself makes use of the past and intervene in this.
Elaborating on the compatibility between genealogy and elements of the contextual approach to history associated with the ‘Cambridge School’, this article challenges recent suggestions that anachronism is irrelevant, unavoidable, or even a ‘method’ that might be fruitfully embraced in studies of international law’s past directed towards explaining and potentially altering its present. It argues that historians of international law should take the dangers of anachronism seriously, particularly if the histories they develop are to operate as a form of critique and basis for change. Genealogy is a form of history that allows a particularly potent critique of international legal thought and practice. It opens up possibilities for more radical change by questioning and moving beyond the normative framework that usually structures (and limits) calls for reform in international law.