The law of the virtual Roman Empire persisted throughout the Middle Ages, combined with customary law, like Salic law, or Saxon Law. Roman law was rediscovered and studied in the first universities in Western Europa. Legal scholars of the day made comments and thus developed so-called canon law: a mix of roman, medieval and religious law. At the same, as a result of feudal relations, quid pro quo documents, like the magna Charta and Joyous entries, emerged, granting different classes different privileges and rights in turn for assistance, tax and loyalty to a ruler. This marked the beginning of conditional power and the rule of law.

As the noble elites in Elizabethan England were preparing their anti-imperial and anti-papal strategies, they received welcome assistance from the civil lawyer Alberico Gentili, a protestant refugee interested in combining his Roman law expertise with the kind of humanist statesmanship that was appreciated by his English interlocutors and that had flourished among North Italian city-states at the time of Lorenzo de’ Medici. Gentili wrote on the need to combine insights from history with a critical “philosophical” attitude – an orientation he identified in jurisprudence. He insisted on limiting the jurisdiction of theologians to the internal world of the faithful and on the absolute duty of obedience to the king, even when he had turned a tyrant. But Gentili remained blind to the principles of good government that were being developed under the anti-legal vocabulary of the ragion di stato by Italian Counter-Reformation strategists such as Giovanni Botero.

This chapter considers Roman and canon law, the English common law tradition and French juristic thought. Roman and canon law jurisprudence of the fourteenth and fifteenth centuries are taken together because fifteenth-century jurists tended to reiterate the works of fourteenth-century ones. The chapter considers whether jurists contributed to the early development of international law. The impact of humanism on law is also discussed – notably in the case of Lorenzo Valla's destruction of the authenticity of the Donation of Constantine. The English common law tradition is considered through the writings of Sir John Fortescue: notably his justifications of English kingship. The French juristic tradition is considered through its two most important theorists: Jean de Terrevermeille and Claude de Seyssel. Terrevermeille made the most detailed contributions to the notions of the mystical body of the kingdom ever put forward in the Middle Ages. Seyssel, through elaborating the three bridles on royal power (religion, justice and the police) justified an absolute monarchy limited by higher norms, a solution fundamental for centuries throughout the ancien régime

The concept of equity is often assimilated with that of Aristotelian epieikeia, a process that corrects rules when their application to a certain case would be unjust or contrary to the intention of the legislator. In the middle ages - while theologians had written at length on the concept of epieikeia - glossators, commentators, and canonists adopted a concept of aequitas completely unrelated to it. This barrier between law and theology lasted throughout the medieval period. By the mid-sixteenth century the concept of epieikeia had become familiar to legal writers and, through the work of humanist jurists, was explicitly associated with aequitas. The introduction of epieikeia in legal scholarship opened the door to the influence of scholastic theology over the concept of equity, as lawyers and theologians worked together to build a novel concept of aequitas/epieikeia as judicial power to interpret law beyond its letter.

How did European thinking about interactions with peoples of the Indies move from Christian-infidel relations to an identifiably modern form of international relations? This chapter explores the preceding question by looking at the emergence of Protestant empires during the seventeenth-century and the ascendant neo-Stoic Christian legal humanism structuring new ideas of world order and providential commerce. It considers the growing ideological displacement of the legal category of the infidel, and the associated crime of idolatry, in the political context of the Indies, East but especially West. This chapter also addresses normative ideas about the savage that developed in the infidel’s wake. Although there were important differences between the Iberian empires and the new English and Dutch empires, there were also continuities. This chapter considers those similarities between Spanish religious thinkers and representative international thinkers on natural law and the law of nations such as Alberico Gentili, Hugo Grotius, Samuel Purchas, New England Puritans, and John Locke. What does the colonization of North America look like in light of Valladolid’s legacy from a century earlier?