"They also agreed that after Christmas they would go all together to the King and ask him for a confirmation of these liberties, and that meanwhile they would so provide themselves with horses and arms that if the King should seek to break his oath, they might, by seizing his castles, compel him to make satisfaction.

And when these things were done every man returned to his own home."[11] John now asked for time to consider these requests, and for the next six months worked hard to break up the barons' confederacy, to gain friends and supporters, and to get mercenaries from Poitou.

It was all to no purpose.
As a last resource he took the Cross, expecting to be saved as a crusader from attack, and at the same time he wrote to the Pope to help his faithful vassal.

The Pope's letters rebuking the barons for conspiracy against the King were unheeded, and the mercenaries were inadequate when John was confronted by the whole baronage in arms.
THE GREAT CHARTER In May a list of articles to be signed was sent to John; and on his refusal the barons formally renounced their homage and fealty and flew to arms.
John was forced to surrender before this host.

On June 15th he met the barons at Runnymede, between Staines and Windsor, and there, in the presence of Archbishop Stephen and "a multitude of most illustrious knights," sealed the Great Charter of the Liberties of England.
This Great Charter was in the main a renewal of the old rights and liberties promised by Henry I.It set up no new rights, conferred no new privileges, and sanctioned no changes in the Constitution.