It is always important to have established means of resolving conflict and disagreement. In medieval societies, as in most, there were many such means, some more formal and institutional than others. But , as I noted, allegiances were multiple, jurisdictions frequently overlapped, and there often were significant disagreement and conflicts among the governing bodies and persons. In the absence of an unambiguous and widely acknowledged hierarchy of authorities, resolutions might be ineffective. Without a single, ultimate source of political power within a domain, many have thought disagreements could not be ‘decided’, expect by force. This possibility may be looked upon with alarm, especially given the ferocity of much human conflict. The more serious the conflicts between people, the more pressing the question ‘who decided?’ is likely to be. ‘To decide’ a matter, in this sense, is frequently understood to mean to be ‘the final arbiter’. In Christendom this could only be God and, in the event that his word would require frequent interpretation, the Church. Indeed, the very notion of a final arbiter seemed to presuppose a cosmological hierarchy like that provided by Christian monotheism. The state’s answer to the question ‘who decides?’ is to put itself in the Church’s place, or rather, God’s place-‘le princeest image de Dieu’(Bodin, 1583: I, ch. VIII,137). It, and only it, is the final arbiter, at least locally, on matters that pertain to it. To assert this, states had to contest the Church’s authority. They had, as well, to contest the power of ‘internal’ rival, namely, feudal lords. Emerging from these contests is the modern notion of sovereignty: the state is the ultimate source of political power within its realm.