The Authority to Make Treaties in the Late Middle Ages

Abstract

Marc Bloch's aphorism-the past serves to understand the present; the present helps to understand the past'-seems particularly apt when one considers the continuing debates on the legitimacy of transfers or delegations of sovereignty by treaty2 (for example, the Panama Canal Treaties, the Treaty on European Union, NAFTA, GATT/WTO, and even the Charter of the United Nations). With this continuity in mind, in this article I explore the medieval sources of the modern law of treaties, especially those that concern the authority to conclude treaties transferring aspects of. sovereignty from one prince to another. Treaty-making power is often considered a modem concept. Peter Haggenmacher writes that it unknown to Hugo Grotius and first developed in the eighteenth-century writings of Christian Wolff and Emmerich de Vattel. By elaborating the idea that the treaty-making power should be shared by the king and the people or a restricted council, they enhanced the role of the state, rather than that of the sovereign, as the ultimate bearer of the right to make treaties.3 Treaty making, according to Wildhaber, was an incident of the sovereign power which lay in the hands of the monarchs.4 Thus, he claims, when the Kings of France submitted treaties to the Etats Generaux for discussion or approval, they did so not because of any legal duty, but because the other party had demanded an additional guarantee of