In 1215, the Barons of England forced King John to sign a revolutionary document which would change the political landscape of Britain and beyond for the next 800 years. Magna Carta was the forerunner of the Constitution that limited the powers of the crown and its echoes can be found in the seventeenth century Civil Wars, the struggles for American Independence, the work of Thomas Paine and in the bedrock of all contemporary liberal nations. As civil liberties and the rule of law are increasingly under question as part of the 'War on Terror', it has never been more essential to return to the original document, signed at Runnymede in June 1215. Leading medieval historian Geoffrey Hindley retells the story of events leading up to the conference and looks at the document itself, showing how it has resonated over centuries and throughout the world.