As increasingly recognized, medieval and early modern corporations were influential models for the emerging European state. E E xisting scholarship documents the influence of the corporation’s constitutionalism on the constitutionalism of the state. T T his article documents the separate influence of the corporation in imparting “juridical personhood” to the state – —the capacity to own and contract as an individual. T T his is a feature of all modern states, regardless of constitutional order, that vastly augments their power and makes possible the current international state system. C C ontrary to reigning assumptions, it did not automatically follow from borrowing the corporation’s constitutional structure, but was a distinct historical development. J J uridical personhood passed from the (corporate) bishopric to the kingdoms of Europe via the medieval bishop–~king analogy. T T he chapter examines this history in England and the Continent, then relates how the American founders resolved the longstanding tension between state sovereignty and state juridicality, i.e.that is, that the state is sovereign yet is under the rule of law and, for example, bound by its contracts. T T he chapter also clears up some modern conceptual confusions regarding peoples, states, and governments.