Editing John, King of England (section)

===Pre-war tensions and Magna Carta===
[[File:Magna Carta (British Library Cotton MS Augustus II.106).jpg|thumb|upright=1.5|alt=A photograph of a page of Magna Carta, a wide page of dense, small medieval writing.|One of four surviving original copies of Magna Carta, agreed by John and the barons in 1215. [[British Library]], London.]]

Within a few months of John's return, rebel barons in the north and east of England were organising resistance to his rule.<ref>Turner, p. 174.</ref> John held a council in London in January 1215 to discuss potential reforms and sponsored discussions in Oxford between his agents and the rebels during the spring.<ref name="TurnerP178">Turner, p. 178.</ref> He appears to have been playing for time until Pope Innocent III could send letters giving him explicit papal support. This was particularly important for John, as a way of pressuring the barons but also as a way of controlling Stephen Langton, the Archbishop of Canterbury.<ref>Turner, p. 179.</ref> In the meantime, John began to recruit fresh mercenary forces from Poitou, although some were later sent back to avoid giving the impression that John was escalating the conflict.<ref name=TurnerP178/> The King announced his intent to become a crusader, a move which gave him additional political protection under church law.<ref>Warren, p. 233.</ref>

Letters of support from the Pope arrived in April but by then the rebel barons had organised. They congregated at [[Northampton]] in May and renounced their feudal ties to John, appointing [[Robert fitz Walter]] as their military leader.<ref>Turner, pp. 174, 179.</ref> This self-proclaimed "Army of God" marched on London, taking the capital as well as [[Lincoln, England|Lincoln]] and [[Exeter]].<ref name="TurnerP180">Turner, p. 180.</ref> John's efforts to appear moderate and conciliatory had been largely successful, but once the rebels held London they attracted a fresh wave of defectors from John's royalist faction.<ref name=TurnerP180/> John instructed Langton to organise peace talks with the rebel barons.<ref name=TurnerP180/>

John met the rebel leaders at [[Runnymede]], near [[Windsor Castle]], on 15 June 1215.<ref name=TurnerP180/> Langton's efforts at mediation created a charter capturing the proposed peace agreement; it was later renamed [[Magna Carta]], or "Great Charter".<ref>Turner, pp. 180, 182.</ref> The charter went beyond simply addressing specific baronial complaints, and formed a wider proposal for political reform, albeit one focusing on the rights of free men, not serfs and [[unfree labour]].<ref>Turner, p. 182.</ref> It promised the protection of church rights, protection from illegal imprisonment, access to swift justice, new taxation only with baronial consent and limitations on [[scutage]] and other feudal payments.<ref>Turner, pp.&nbsp;184–185.</ref> A council of twenty-five barons would be created to monitor and ensure John's future adherence to the charter, whilst the rebel army would stand down and London would be surrendered to the King.<ref name="TurnerP189">Turner, p. 189.</ref>

Neither John nor the rebel barons seriously attempted to implement the peace accord.<ref name=TurnerP189/> The rebel barons suspected that the proposed baronial council would be unacceptable to John and that he would challenge the legality of the charter; they packed the baronial council with their own hardliners and refused to demobilise their forces or surrender London as agreed.<ref>Turner, pp. 189–190.</ref> Despite his promises to the contrary, John appealed to Innocent for help, observing that the charter compromised the Pope's rights under the 1213 agreement that had appointed him John's feudal lord.<ref name="TurnerP190">Turner, p. 190.</ref> Innocent obliged; he declared the charter "not only shameful and demeaning, but illegal and unjust" and excommunicated the rebel barons.<ref name=TurnerP190/> The failure of the agreement led rapidly to the [[First Barons' War]].<ref name=TurnerP190/>