Compact and well-written, Jennifer Pitts’s Boundaries of the International joins a growing field of inquiry into the history of international law. Pitts sets out to challenge what she sees as the discipline’s conventional narrative: that international law emerged first between free and sovereign European nations, creating an ecumene that other states would aspire to join. Instead, she shows, ideas about the ‘law of nations’, as it was long called, were from their beginning shaped by European commercial and colonial expansion. International legal discourse, Pitts argues, supplied both justifications for conquest and resources for a critique of the abuses of imperial power.