When John learnt that his brother was on his way to Acre, he took active measures for bringing his schemes into operation. Various disputes took place between him and the chancellor, and before long an incident occurred which led to an open rupture between them. Gerald of Camville, a Norman baron, and one of the adherents of John, held the custody of Lincoln Castle, which he had purchased from the king. Longchamp--who, it is said, desired to give this office to one of his friends--summoned Camville to surrender the keys of the castle; but the baron refused compliance, saying that he was Earl John's liegeman, and that he would not relinquish his possessions except at the command of his lord. Longchamp then appeared before Lincoln with an army, and drove out Camville, who appealed to John for justice. The prince, who desired nothing better than such an opportunity, attacked the royal fortresses of Nottingham and Tickhill, carried them with little or no opposition, and, planting his standard on the walls, sent a messenger to Longchamp to the effect that, unless immediate restitution were made for the injury to Gerald of Camville, he would revenge it with a rod of iron. The chancellor, who possessed little courage or military talent, entered into a negotiation, by the terms of which the castles of Nottingham and Tickhill remained in the hands of John, and that of Lincoln was restored to Camville. Others of the royal castles, which had hitherto remained exclusively in the power of the chancellor, were committed into the custody of different barons, to be retained until the return of Richard from the Holy Land, or, in the event of his death, to be delivered up to John. These important concessions satisfied John only for a short time, and an opportunity soon presented itself for pushing his demands further. Geoffrey, son of Henry II. by Fair Rosamond, had been appointed to the archbishopric of York during his father's lifetime, but his consecration had been delayed until the year 1191, when the necessary permission was received from the court of Rome, and he was consecrated by the Archbishop of Tours. As soon as the ceremony was concluded, he prepared to take possession of his benefice, notwithstanding the oath which had been exacted from him that he would not return to England. The chancellor having been apprised of his intention, sent a message to him forbidding him to cross the Channel, and at the same time directed the sheriffs to arrest him should he attempt to land. Geoffrey despised the prohibition; and, having landed at Dover in disguise, took shelter in a monastery. His retreat was soon discovered, and the soldiers of the king broke into the church, and seized the archbishop at the foot of the altar, while he was engaged in the celebration of the mass. A good deal of unnecessary violence seems to have been used, and Geoffrey was dragged through the streets to Dover Castle, where he was imprisoned.