Common Law Assent

The circumstances under which King John was obliged to put his seal to the Magna Carta are not those of a rebellious or unlawful "duress." On the contrary, it is an assertion of ignorance or falsification to make such a claim. The point to appreciate is that at his coronation, King John had subjected and bound himself by oath under the law of the land and charter ratified by his forebear Henry the First and his successors.