Magna Carta, or "great charter," is the charter of English liberties granted by King John (r. 1199-1216) in 1215 and modified during the reign of Henry III (r. 1216-72) in 1216, 1217, and 1225. This document is the first systematic elaboration of the fundamental idea of rule by law, and one of the first examples in western Europe of an appeal to written law as opposed to custom.
The barons of England forced Magna Carta on King John because he was abusing his royal power. The Angevin Empire (consisting of England and most of France) established by Henry I (r. 1100-1135) and Henry II (r. 1154-1189) had fallen on hard times. John's military misfortunes were expensive, and he became ruthless in raising cash. The unpopularity engendered by his loss of England's French possessions and his style of ruling was heightened by his quarrel with Pope Innocent III (r. 1198-1216). The lay investiture question became an issue again after the pope quashed John's choice for the archbishop of Canterbury. In the end John was forced to accept Innocent's nominee, Stephen Langton (1150-1228), and become the pope's vassal.
With at least Langton's tacit support, the barons of England rebelled against John in 1214. After a brief civil war, John capitulated to the barons' demands, and in 1215 at Runnymede he granted Magna Carta, which became a symbol of liberty and constitutional government for future generations. It is a part of the written and unwritten constitution that still governs England, and the liberties it grants have made their way into the laws of many other countries. Article 39, for instance, is the historical origin of the English Habeas Corpus Act of 1679: "No free man shall be taken or imprisoned or disseised or outlawed or exiled or in any way ruined, nor will we go or send against him, except by the lawful judgment of his peers or by the law of the land."1
Magna Carta is the first modern statement of the idea that a ruler is bound by the rule of law. Many of the traditions and customs associated with Germanic kingship, which rulers often ignored, were positively established as law by Magna Carta. Germanic custom, for instance, called for a group of barons to advise the king, but Magna Carta ensured this process by binding the king and lords in an explicit and written contract.
 J.C. Holt, Magna Carta (Cambridge: Cambridge University Press, 1991), p. 461.
The introduction to the Text originally appeared on The Goodrich Room: Interactive Tour website.
Last modified April 13, 2016