Magna Carta reflects two distinct conditioning circumstances. On the one hand it emerged from the increasing maturity of European political thought and practice, from the concept of rule according to law, from the demand for the preservation of the rights of subjects within a feudal and ecclesiastical hierarchy and from routine patterns of government which went with more disciplined and sophisticated forms of administration. On the other hand it was a product of a political crisis. It sprang directly from the flexibility and severity of Angevin methods of government under the ruthless and capable direction of King John, from the urgent requirements imposed by foreign wars for the defence and, after 1204, the recovery of Normandy, and from the final collapse of John's military and diplomatic schemes on the field of Bouvines in July 1214.

Thus the Charter was not simply a statement of administrative practices, or desired regulations or principles of law. These were no more than the terms of reference establishing broad limits within which the opposing parties made their demands, or compromised and hedged, or sought hidden advantages, or skilfully provided escape routes from the letter of the documents. The Charter and its associated documents are complex records which bear the imprint of nearly three years of political crisis and protracted, discontinuous negotiation. They cannot be properly understood apart from this crisis, for to separate them from the detail of politics is to risk anachronism and to hinder our understanding of the relative importance which men then attached to particular issues and demands. By 1215 negotiation had acquired a momentum of its own, and particular details had achieved a crucial significance out of all proportion to their ultimate effects, if any, on the course of English history. Thus the restoration of a castle, the claim to an inheritance, the dismissal of a royal official, and issues such as these, became nodal points, important both in themselves and as tests of the king's good faith, from which there grew suspicion, mistrust and civil war.