That battle was the culmination of a financially ruinous campaign when he was attempting to regain the French possessions of his forefathers.
John returned to England, therefore, with his tail between his legs. The war had essentially made him bankrupt and so it was that he needed the financial support of the nobles. No longer could he ignore the demands of the Barons and so he was forced to negotiate. The fruit of those discussions was Magna Carta. One of the most famous of its promises is:
No free man shall be seized or imprisoned, or stripped of his rights or possessions, or outlawed or exiled, or deprived of his standing in any other way, nor will we proceed with force against him, or send others to do so, except by the lawful judgement of his equals or by the law of the land. To no one will we sell, to no one deny or delay right or justice.
The intrinsic adaptability of that clause has allowed succeeding generations to reinterpret it for their own purposes. In the 14th century Parliament saw it as guaranteeing trial by jury; in the 17th century Sir Edward Coke saw it as a declaration of individual liberty in the conflict of Parliament with Charles I and it has echoes in the American Bill of Rights (ratified in 1791) and the Universal Declaration of Human Rights (1948).
Magna Carta also stated that no taxes could be demanded without the “general consent of the realm”, meaning the leading barons and churchmen. Despite the fact that John successfully petitioned the Pope to have the Charter annulled within six months of it having been sealed, his successors, seeking stability, were forced to re-issue it and so it became part of the law of the land.
So why is this apparently insignificant piece of parchment of such colossal importance today? Well, first because it placed limits upon the Crown when it came to the exercising of its prerogative rights. But it also led to a much more wide-ranging development. Because it had been explicitly granted in return for the payment of tax, it paved the way for the first Parliament to be summoned in order that approval could be given to the granting of tax-raising powers to the king. And because any king is powerless without money, the fact that the king has to seek the approval of the people for the levying of tax means that the Crown was forever thereafter subject to the will of the people, expressed through Parliament, whenever money was needed.
But that is to look at Magna Carta in a literal sense. Whatever the limitations are on the actual words, it is the spirit of Magna Carta that has had most influence. The fact that the Crown has, from a very early date, been used to having to go to Parliament to seek approval for its actions, has engendered a sense, in the executive, of restraint and what we would now call proportionality. Magna Carta exemplifies an ethos within which executive action has been framed. It enshrines the concept of the rule of law. That is its philosophical legacy.
But that philosophical legacy is broader than it first appears. It carries with it the functional or practical legacy of Magna Carta.
It is simpler to earn your living by robbery than it is to work long hours and sacrifice many of the enjoyments of family life. So, why is it that people do not simply commit crime to finance their lives rather than working for their living?
I suggest it is because people, although never wholly contented, take the view that society is equitable, tolerant and fair. And one of the chief reasons why they think that is because they know that no-one is above the law. In other words, the principles enshrined in Magna Carta have led to the very practical doctrine of accountability.
In addition, because of its specific promises, people in the UK do not live in fear of the knock on the door in the middle of the night or the risk of arbitrary arrest without recourse to law.
But all is not well. The charter provides a guarantee of access to justice. That is why the Bar has been so opposed to the effects of the Legal Aid, Sentencing and Punishment of Offenders Act 2012 and the huge hike in court fees, as these strike at the very substance of that Magna Carta promise.
For all these reasons, I am convinced that the principles of Magna Carta are as important today as they were in 1215. It is a terrible irony that, as we celebrate Magna Carta, it is being undermined by an executive which pays lip service to its principles. If the legacy of Magna Carta is to last another 800 years, it requires everyone with a sense of history and an understanding of the critical importance of the rule of law to stand up and fight for it. The liberties conferred by this great document were hard won. We owe it to posterity to ensure that they are not lost in our time.
Alistair MacDonald QC, Chairman of the Bar