We investigate the nature and significance of the vital but neglected “company-states” in helping to facilitate the move from contained regional international systems to the first genuinely global international system. Historically, actors like the Dutch and English East India Companies were crucial in spearheading the first wave of European expansion in Asia, Africa, and the Americas. Conceptually, company-states broaden our understanding of international actors. At a time when intra-European politics favored gradual institutional convergence on the sovereign state, the demands of extra-European expansion meanwhile gave rise to diverse competing institutions. Company-states succeeded in an era of weak sovereign states because of their relative efficiency in managing the transaction costs and principal-agent challenges of intercontinental trade and rule. Conversely, company-states later declined as they succumbed to the effects of sharpening worldwide geopolitical competition, and were displaced by increasingly powerful new European empire-building projects. This argument advances earlier work on the creation of the international system by eschewing Eurocentrism and state-centrism, and foregrounding diversity and hybridization.