What happened
Facing armed baronial revolt, John accepted a 63-clause charter limiting arbitrary royal power — most famously that no free man be imprisoned or dispossessed except by lawful judgment of his peers or the law of the land, and that justice be neither sold nor delayed.
Background
John’s heavy taxation and military failure in France — capped by defeat at Bouvines in 1214 — drove the barons to rebellion. The charter was a peace treaty as much as a statement of principle, and Pope Innocent III annulled it within weeks, reopening the war.
Consequences
Reissued under Henry III (1216, 1217, and 1225, the definitive text), Magna Carta became a touchstone invoked by Parliament against the Stuarts and echoed in later documents from the US Constitution to human-rights charters. Four copies of the 1215 issue survive.