When and how did international law become a universal order applicable to all states on the earth? Existing scholarship has framed the universalization of international law in one of two ways. Traditionally, scholars have analyzed this legal process with reference to European global imperial expansion during the nineteenth-century and the concomitant legal domination of non-European societies. More recently, however, scholars have analyzed this process of legal universalization with reference to non-European states’ legal resistance to European imperial domination, and specifically their critical re-appropriation of European international law as an anti-imperial counter-discourse. This historiographical opposition, I argue, was mirrored in an historical opposition between nineteenth-century European imperial jurisprudence and non-European anti-imperial jurisprudence. Viewed together, historically, these discursive oppositions raise heretofore largely overlooked questions about the kinds of global practices that underpinned the universalization of modern international law, and rendered its attendant imperial/anti-imperial counter discourses equally plausible to both sides. My proposed book analyzes the historical nature and significance of those practices through an investigation of the global spread and deepening of commodity exchange relations, which, I argue, necessitated a particular liberal form of private law and rights-bearing legal subject. That liberal form of private law structured the historical constitution of nineteenth-century public law, including, most significantly, modern “universal” international law. It did so by supplying and lending legal legitimacy to the latter’s core liberal normative assumptions, rendering their derivative legal-jurisprudential imperial and anti-imperial discourses plausible to both European and non-European legal actors. It is in this critical frame, I argue, that we should understand the dual nature and significance of modern liberal international law, and the paradoxical historical trajectories borne out through its universalization.