In 1215 a rebellion of English barons forced King John to seal Magna Carta at Runnymede, conceding that the crown's power was bound by established law and customary liberties. The charter explicitly confirmed the ancient liberties and free customs of the City of London and other towns, alongside clauses on lawful judgement and the seizure of property. Though annulled within months and reissued in revised form, its principles of due process survived in later English law. Its guarantees against arbitrary imprisonment and dispossession proved its most durable legacy.
It anchored the enduring idea that authority over persons and property is constrained by law rather than royal will. In doing so it also affirmed the chartered self-government and customary liberties of medieval towns.