When Europeans arrived in the New World, they had to establish and maintain a claim to the land they had seen that would be respected by the other European powers. One legal doctrine, the Right of Discovery, conveyed to European monarchs the right to claim lands discovered in his or her name so long as they had not already been claimed by another Christian people. As such the Pope was an important adjudicator of disputes between Christian peoples, such as happened in the Treaty of Tordesillas (1494). When the French began exploring the New World, they challenged the Iberian kingdoms' Rights to Discovery and claimed that the right did not pertain to land that had not actually been explored. The French and the English proposed an alternative theory called the Right of Conquest. Only by conquering native populations and by building permanent...