The Magna Carta was a seminal document that entrenched the principle of the “rule of law” as it now informs British life.

Here at the beginning of the 21st century, it has become a common expectation around the world that people should benefit from laws that protect fundamental fairness and human dignity — for instance, that the right to a fair trial doesn’t depend on your postcode, passport, bank balance or skin colour. Many of those fundamental human rights were enshrined in the Magna Carta.

Imposed on King John by rebel barons on June 15, 1215, the Magna Carta limited the power of the monarch and confirmed the rights of people under common law. It is an important ancestor of the Human Rights Act of 1998.

The charter contains 63 clauses. Some of them are narrow and quite technical. For example, clause (23): “no town or man should be distrained [have goods confiscated to force someone to act] to make bridges at river banks, unless anciently and of right bound to do so”.

The sum total of all the clauses did, though, help re-tilt the power balance between the monarch and the population. Clauses 39 and 40 state that, “No freeman shall be arrested, or detained in prison, or disseised [deprived of his freehold], or outlawed, or exiled, or in any way molested . . . except by the lawful judgment of his peers and by the law of the land. To no one will we sell, to no one will we deny or delay, right or justice.”

At the time, the charter was in many ways ineffective. Its provisions didn’t work in practice. It failed in its intention to avoid a war between King John and his barons. Fighting continued. In fact, the reason copies of the charter were made and circulated throughout the kingdom was that the barons wanted to ensure the king would have a hard time trying to go back on what had been agreed. John was pushed northwards, lost his entire treasury to the sea and died the following year.

Ultimately, however, the Magna Carta would come to inspire the development of the English legal and parliamentary system — it is also hard-wired into the genetic codes of the constitutions of many of the Commonwealth countries. It has come to be commonly accepted that it is desirable to be ruled by democratically-passed laws and not by the capricious will of a ruler. Sometimes, if a politician exceeds the authority given to him, the rule of law does not prevail. But most such attempts are controlled by the courts or the threat of legal action in the traditions of British fair play. Our courts, for example, have ruled that the Government’s attempts to lock up terrorist suspects indefinitely without a trial are unlawful.

Putting the law of the land above the heads of politicians is crucial to a flourishing democracy. For that reason, the signing of the Magna Carta should be celebrated as a great day in our history.

Gary Slapper is Professor of Law and Director of the Centre for Law at the Open University

Explore Law

• Columnists

• Law Panel

• Law Reports

• Student Law

Times Recommends

• BGC 'set aside £40m to lure Tullett brokers'
• Legal aid review to ensure value
• Fears as 21 magistrates' courts face closure