 Both sides appealed to Pope Innocent III for assistance in the dispute.During the negotiations, the rebellious barons produced an initial document, which historians have termed "the Unknown Charter of Liberties", which drew on Henry I's Charter of Liberties for much of its language; seven articles from that document later appeared in the "Articles of the Barons" and the subsequent charter.It was John's hope that the Pope would give him valuable legal and moral support, and accordingly John played for time; the King had declared himself to be a papal vassal in 1213 and correctly believed he could count on the Pope for help.