The most important letter we know:Magna Carta

Magna carta cum statutis angliae, (Great Charter with English Statutes) page 1 of manuscript, fourteenth century

Magna Carta was the first document forced onto an English King by a group of his subjects (the barons) in an attempt to limit his powers by law and protect their privileges. It was preceded and directly influenced by the 1100 Charter of Liberties, when King Henry I had specified particular areas where his powers would be limited.

Any how Magna Carta is an English charter, originally issued in the year 1215, and reissued later in the 13th century in modified versions that omit certain temporary provisions, including the most direct challenges to the monarch's authority.

The charter first passed into law in 1225. The 1297 version, with the long title (originally in Latin) The Great Charter of the Liberties of England, and of the Liberties of the Forest, still remains on the statute books of England and Wales.

Magna Carta was the first document forced onto an English King by a group of his subjects (the barons) in an attempt to limit his powers by law and protect their privileges. It was preceded and directly influenced by the 1100 Charter of Liberties, when King Henry I had specified particular areas where his powers would be limited.

John of England signs Magna Carta. Illustration from Cassell's History of England

The charter was an important part of the extensive historical process that led to the rule of constitutional law in the English speaking world, although it was "far from unique, either in content or form".In practice, Magna Carta in the medieval period did not in general limit the power of kings, but by the time of the English Civil War it had become an important symbol for those who wished to show that the King was bound by the law.

But why all of this

Jurist Edward Coke interpreted Magna Carta to apply not only to the protection of nobles but to all subjects of the crown equally

Over the course of his reign a combination of higher taxes, unsuccessful wars and conflict with the Pope had made King John unpopular with his barons. Some barons began to conspire against him in 1209 and 1212; promises made to the northern barons and John's submission to the papacy in 1213 delayed a French invasion.

In 1215 some of the most important barons engaged in open rebellion against their King. This was not unusual; every king since William the Conqueror had faced rebellions. However, in every previous case there had been an obvious alternative monarch around whom the rebellion could rally. In 1215 however John had no obvious replacement. Arthur of Brittany would have been a possibility, if he had not disappeared (widely believed to have been murdered on the orders of John). The next closest possible alternative was Prince Louis of France, but as the husband of Henry II's granddaughter, his claim was tenuous, and the English had been at war with the French for thirty years. Instead of a claimant to the throne, the barons decided to base their rebellion around John's oppressive government. In January 1215 the barons made an oath that they would "stand fast for the liberty of the church and the realm", and they demanded that King John confirm the Charter of Liberties, from what they viewed as a golden age.

John prevaricated. During negotiations between January and June 1215, a document was produced, which historians have termed 'The Unknown Charter of Liberties', seven of the articles of which would later appear in the 'Articles of the Barons' and the Runnymede Charter. In May, King John offered to submit issues to a committee of arbitration with the Pope as supreme arbiter, but the barons continued in their defiance. With the support of Prince Louis the French Dauphin and of King Alexander II of the Scots, they entered London in force on 10 June 1215, with the city showing its sympathy with their cause by opening its gates to them. They, and many of the moderates not in overt rebellion, forced King John to agree to a document later known as the 'Articles of the Barons', to which his Great Seal was attached in the meadow at Runnymede on 15 June 1215. In return, the barons renewed their oaths of fealty to King John on 19 June 1215. The contemporary, but unreliable chronicler, Roger of Wendover, recorded the events in his Flores Historiarum. A formal document to record the agreement was created by the royal chancery on 15 July: this was the original Magna Carta, though it was not known by that name at the time. An unknown number of copies of it were sent out to officials, such as royal sheriffs and bishops.

John of England signs Magna Carta. Illustration from Cassell's History of England (1902)

1297 copy of the Magna Carta, owned by the Australian Government and on display in the Members' Hall of Parliament House, Canberra.

The 1215 document contained a large section which is now called clause 61 (the original document was not actually divided into clauses). This section established a committee of 25 barons who could at any time meet and overrule the will of the King if he defied the provisions of the Charter, seizing his castles and possessions if it was considered necessary. This was based on a medieval legal practice known as distraint, but it was the first time it had been applied to a monarch.

Distrust between the two sides was overwhelming; what the barons really sought was the overthrow of the King, the demand for a charter was a "mere subterfuge". Clause 61 was a serious challenge to John's authority as a ruling monarch. He renounced it as soon as the barons left London; Pope Innocent III also annulled the "shameful and demeaning agreement, forced upon the King by violence and fear." He rejected any call for restraints on the King, saying it impaired John's dignity. He saw it as an affront to the Church's authority over the King and the 'papal territories' of England and Ireland, and he released John from his oath to obey it. The rebels knew that King John could never be restrained by Magna Carta and so they sought a new King.

England was plunged into a civil war, known as the First Barons' War. With the failure of Magna Carta to achieve peace or restrain John, the barons reverted to the more traditional type of rebellion by trying to replace the monarch they disliked with an alternative; in a measure of some desperation, despite the tenuousness of his claim, despite the fact that he was French, they offered the crown of England to Prince Louis of France.

Magna Carta Place, within Canberra, Australia's Parliamentary Triangle opened on 24 May 2003

As a means of preventing war the Magna Carta was a failure, rejected by the most of the barons, and was legally valid for no more than three months. It was the death of King John in 1216 which secured the future of Magna Carta