Magna Carta and its many contemporaries were not innovations. John Lackland and his kingly brethren were the innovators. Magna Carta was an attempt to suppress innovation. Even the Parliament that the younger de Montfort organized was a conservative innovation. Longshanks discovered he could subvert Montfort’s initiative to triangulate between rising burgesses and sitting nobles to radically increase the power of the crown.

Even then innovation was frowned upon well into the seventeenth century. Parliament’s role was not the manufacture of new law but the protection and promotion of ancient law based on precedent. This is why Coke resuscitated the forgotten Magna Carta in his battle against Stuart absolutist innovations. Only later did the burgesses discover that they could triangulate between crown and nobility to increase its power. But that’s another story.