King John (ruled 1199–1216) was unpopular with the leading noblemen (barons) of his day. They objected to his high levels of taxation and the loss of English lands in France after 1204. The barons were also displeased by John’s bitter quarrel with the Pope over who was to be Archbishop of Canterbury, a dispute that led to many church services being banned. Following a disastrous defeat John suffered at the hands of the French, the barons rebelled. On 15th June 1215, they forced John to agree to Magna Carta (Great Charter), a list of demands by which the barons attempted to limit the power of the sovereign and gain rights for themselves.

Loss of Normandy

When John ascended to the the English throne, English kings owned much of northern and western France—the Angevin Empire. In 1201 a powerful alliance of French nobles from Normandy, the Lords of Lusignan, rebelled against John, their feudal lord, over John's decision to marry Isabella of Angoulême, who was already engaged to Hugh de Lusignan. Although John crushed the uprising, King Philip II of France invaded Normandy, and, in 1204, drove the English out. Philip then advanced south to occupy Anjou and Poitou as well. John's only remaining possession in France was now the Duchy of Aquitaine.

John inherited a weakened monarchy from his brother Richard I (Richard the Lionheart). Richard had spent all the money in the Treasury on his crusades, and, when he was captured, for his ransom. Richard lived in England for only seven months of his 10-year reign, leaving the business of governing to clerks and court advisers. In Richard's absence, the barons, who held most of the country's lands, became more powerful.

​​​​​​​John tried to strengthen the monarchy. He improved its finances through raising a new land tax from the barons and re-established control over northern England, Ireland and Wales, while maintaining friendly relations with William the Lion, King of Scotland. In 1205, John tried to force the Church to accept his candidate for Archbishop of Canterbury, but the Church insisted it had the sole right to elect the Archbishop. Pope Innocent III resolved the dispute by appointing his own candidate, Stephen Langton. When John objected, Innocent prevented English priests from holding religious services (the "interdict") and excommunicated John between 1209 and 1213.
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Battle of Bouvines

John mounted a campaign to reconquer Normandy, raising extensive taxes on the barons to accumulate the money he needed to do so. However, his forces were crushed by the French at the Battle of Bouvines in 1214. John asked the barons for more money to finance another campaign in France—but his authority was now completely undermined.

In May 1215, 40 of the rebel barons renounced (vowed to abandon) their feudal ties to the king. With support from the French and Scots, they formed an army, which they called the "Army of God". Under the leadership of Robert Fitzwalter, the rebels marched on Lincoln, Exeter and London.

Once London had fallen to the rebels, John had no alternative but to enter negotiations with them. He instructed Archbishop Langton to arrange peace talks.

King John met the rebels at Runnymede, near Windsor, on 15th June 1215. The rebels presented John with a proposed peace agreement known as the "Articles of the Barons". This was a series of demands for reform which, drafted by Langton, were set out in a charter (it was to be a few years later that this agreement was renamed Magna Carta, meaning "Great Charter"). Agreement was reached, the king's Great Seal was attached to it and, on 19th June, the rebels renewed their oaths of loyalty to John. Copies of the charter were then formally issued.

First Barons' War

The charter—in particular, clause 61—was so heavily weighted against the king that it was highly unlikely it would last for long. Almost immediately, John asked Pope Innocent III for permission to ignore it. As part of the peace agreement, the barons were supposed to surrender London by 15th August, but they refused to do so.

Innocent III then declared the charter to be "not only shameful and demeaning but also illegal and unjust" since John had been "forced to accept" it, and thus the charter was "null, and void of all validity for ever".

Later kings

The charter agreed by John in June 1215—with some clauses, including clause 61, removed and others amended—formed the basis of the peace treaty agreed at Lambeth. The charter now had the name by which we know it today: Magna Carta. Henry re-issued the charter in 1225 in exchange for the granting of new taxes. His son, Edward I, did so once more in 1297. On this occasion, Magna Carta became part of England's statute (written) laws, and remains so today, although most of its clauses have since been repealed.

Legacy

Although Magna Carta was not a declaration of human rights, it was the first time a set of rules had been written down for a king to obey. Many demands were intended to tip the balance of power in favour of the barons. But no monarch of England ever held "absolute" power again. For this reason, Magna Carta is considered to be one of the most important documents in English history.
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