 Magna Carta becomes, if you like, the white noise of political discourse throughout the 17th century. At the start of that century, figures like Sir Edward Cook, great constitutional lawyers, use it in very technical battles between sort of the common law rights of the individual and the king's tyrannical prerogative. By the end of the century, having passed through turbulence of revolution where Magna Carta has been used to justify powerful and sometimes very dangerous resistance to all forms of authority, Magna Carta has become, if you like, the statute that underpins the ancient constitution and the legitimacy of proper government in the UK. Magna Carta was used by the parliamentarians who were struggling against the Stuart kings who believed that they had absolute power. After James died, Charles I came to power and he believed that he had utter and absolute power and when parliament reached for Magna Carta and took their stand on Magna Carta there are limits to your power, they said to the king. And the king, they forced the king initially to agree to the petition of right, later the declaration of right which encapsulated Magna Carta and brought back Magna Carta out of real obscurity. Sir Edward Cook is really responsible for turning what was a rather dull mainstream legal document into a text that justified resistance against the tyrannous use of prerogative by 1st James I and then Charles I. And the essential argument was that Magna Carta protected the freedoms, the lives, liberties and estates of men, free men. Magna Carta became real 400 years ago. In 1628, 1642 it was Magna Carta was the standard under which parliament fought the Civil War and established the real liberties of the subject, the independence of the judiciary an end of torture, abolishing star chamber and the king's power to to irrigate to himself the right to punish people. This was the legacy of Magna Carta, Magna Carta revived and reinterpreted. I think over the course of the long 17th century Magna Carta changed from being a pretty technical elite constitutional legal document very powerful, very important in the ins of court and even perhaps in parliamentary terms to a resource that all sorts of interest groups, whether they were marginal, economic, sort of poor people using Magna Carta to justify resisting paying taxes or radical profits by the end of the 17th century Magna Carta is such a public myth almost that if you want legitimacy in terms of public debate you have to anchor it to your project.