June 2015 will see the 800th anniversary of Magna Carta, the ‘Great Charter’ which was signed at Runnymede by King John to resolve a political crisis he faced with his barons. Buried within its 69 clauses is one of immeasurable importance. This is the idea that no one should be deprived of their freedom without just cause, and that people are entitled to fair trial by their peers according to the law of the land.

At the time Magna Carta did nothing to improve the lot of the vast majority of English people, and all but three of its provisions have been repealed. Yet Magna Carta has come to be seen as the cornerstone of English liberty and an international rallying cry against the arbitrary use of power. It was invoked by opponents of Charles I’s overbearing rule in the 17th century and embodied in the 1791 Bill of Rights in America, where it is still held to have special constitutional status.

Where does Magna Carta stand today? In a time of secret courts in Britain and the Guantanamo gulag, the threat to rights from terror laws and state surveillance of our online activities, do we need to reaffirm its basic principles? Should we take things even further, as Tim Berners-Lee has suggested, and create a new Magna Carta for the worldwide web to protect our liberty online?