In this feudal state, however, a bishop was a baron. The lands which formed the endowment of his office—and in those days endowment could take no other form—constituted a barony. The necessity of a large income and the generosity of the faithful made of his endowment a great fief. It is important to realize how impossible any other conception than this was to the political half of the world. In public position, influence upon affairs, wealth, and popular estimation, the bishop stood in the same class with the baron. The manors which were set aside from the general property of the Church to furnish his official income would, in many cases, provide for an earldom. In fitness to perform the manifold functions of government which fell to him, the bishop far exceeded the ordinary baron. The state could not regard him as other than a baron; it certainly could not dispense with his assistance. It was a matter of vital importance to the king to be able to determine what kind of men should hold these great fiefs and occupy these influential positions in the state, and to be able to hold them to strict accountability. The argument of the state in favour of lay investiture was as sound as the argument of the Church against it.
Here was a conflict of interests in which no real compromise was possible. Incidental features of the conflict might be found upon which the form of a compromise could be arranged. But upon the one essential point, the right of selecting the man, one or the other of the parties whose interests were involved must give way. It is not strange that in the main, except where the temporary or permanent weakness of the sovereign made an exception, that interest which seemed to the general run of men of most immediate and pressing importance gained the day, and the spiritual gave way to the temporal. But in England the conflict was now first begun, and the time of compromise had not yet come. Henry's proposal to Anselm of delay and of a new appeal to the pope was chiefly a move to gain time until the situation of affairs in England should turn more decidedly in his favour. He especially feared, Eadmer tells us, lest Anselm should seek out his brother Robert and persuade him—as he easily could—to admit the papal claims, and then make him king of England.
Robert had returned to Normandy from the Holy Land before the arrival of Anselm in England. He had won much glory on the crusade, and in the rush of events and in the constant fighting, where responsibility for the management of affairs did not rest upon him alone, he had shown himself a man of energy and power. But he came back unchanged in character. Even during the crusade he had relapsed at times into his more indolent and careless mood, from which he had been roused with difficulty. In southern Italy, where he had stopped among the Normans on his return, he had married Sibyl, daughter of Geoffrey of Conversana, a nephew of Robert Guiscard, but the dowry which he received with her had rapidly melted away in his hands. He was, however, now under no obligation to redeem Normandy. The loan for which he had pledged the duchy was regarded as a personal debt to William Rufus, not a debt to the English crown, and Henry laid no claim to it. Robert took possession of Normandy without opposition from any quarter. It is probable that if Robert had been left to himself, he would have been satisfied with Normandy, and that his easy-going disposition would have led him to leave Henry in undisturbed possession of England. But he was not left to himself. The events which had occurred soon after the accession of William Rufus repeated themselves soon after Henry's. No Norman baron could expect to gain any more of the freedom which he desired under Henry than he had had under William. The two states would also be separated once more if Henry remained king of England. Almost all the Normans accordingly applied to Robert, as they had done before, and offered to support a new attempt to gain the crown. Robert was also urged forward by the advice of Ranulf Flambard, who escaped from the Tower in February, 1101, and found a refuge and new influence in Normandy. Natural ambition was not wanting to Robert, and in the summer of 1101 he collected his forces for an invasion of England.
Though the great Norman barons stood aloof from him—Robert of Bellême and his two brothers Roger and Arnulf, William of Warenne, Walter Giffard, and Ivo of Grantmesnil, with others—Henry was stronger in England than Robert. No word had yet been received from Rome in answer to the application which he had made to the pope on the subject of the investiture; and in this crisis the king was liberal with promises to the archbishop, and Anselm was strongly on his side with the Church as a whole. His faithful friends, Robert, Count of Meulan, and his brother Henry, Earl of Warwick, were among the few whom he could trust. But his most important support he found, as his brother William had found it in similar circumstances, in the mass of the nation which would now be even more ready to take the side of the king against the Norman party.
Henry expected the invaders to land at Pevensey, but apparently, with the help of some part of the sailors who had been sent against him, Robert landed without opposition at Portsmouth, towards the end of July, 1101. Thence he advanced towards London, and Henry went to meet him. The two armies came together near Alton, but no battle was fought. In a conflict of diplomacy, Henry was pretty sure of victory, and to this he preferred to trust. A meeting of the brothers was arranged, and as a result Robert surrendered all the real advantages which he had crossed the channel to win, and received in place of them gains which might seem attractive to him, but which must have seemed to Henry, when taken all together, a cheap purchase of the crown. Robert gave up his claim to the throne and released Henry, as being a king, from the homage by which he had formerly been bound. Henry on his side promised his brother an annual payment of three thousand marks sterling, and gave up to him all that he possessed in Normandy, except the town of Domfront, which he had expressly promised not to abandon. It was also agreed, as formerly between Robert and William Rufus, that the survivor should inherit the dominions of the other if he died without heirs. A further provision concerned the adherents of each of the brothers during this strife. Possessions in England of barons of Normandy, which had been seized by Henry because of their fidelity to Robert, should be restored, and also the Norman estates of English barons seized by Robert, but each should be free to deal with the barons of his own land who had proved unfaithful. This stipulation would be of especial value to Henry, who had probably not found it prudent to deal with the traitors of his land before the decision of the contest; but some counter-intrigues in Normandy in favour of Henry were probably not unknown to Robert.
Robert sent home at once a part of his army, but he himself remained in England long enough to witness in some cases the execution by his brother of the provision of the treaty concerning traitors. He took with him, on his return to Normandy, Orderic Vitalis says, William of Warenne and many others disinherited for his sake. Upon others the king took vengeance one at a time, on one pretext or another, and these included at least Robert of Lacy, Robert Malet, and Ivo of Grantmesnil. The possessions of Ivo in Leicestershire passed into the hands of the faithful Robert, Count of Meulan—faithful to Henry if not to the rebel who sought his help—and somewhat later became the foundation of the earldom of Leicester.
Against the most powerful and most dangerous of the traitors, Robert of Bellême, Henry felt strong enough to take steps in the spring of 1102. In a court in that year Henry brought accusation against Robert on forty-five counts, of things done or said against himself or against his brother Robert. The evidence to justify these accusations Henry had been carefully and secretly collecting for a year. When Robert heard this indictment, he knew that his turn had come, and that no legal defence was possible, and he took advantage of a technical plea to make his escape. He asked leave to retire from the court and take counsel with his men. As this was a regular custom leave was granted, but Robert took horse at once and fled from the court. Summoned again to court, Robert refused to come, and began to fortify his castles. Henry on his side collected an army, and laid siege first of all to the castle of Arundel. The record of the siege gives us an incident characteristic of the times. Robert's men, finding that they could not defend the place, asked for a truce that they might send to their lord and obtain leave to surrender. The request was granted, the messengers were sent, and Robert with grief "absolved them from their promised faith and granted them leave to make concord with the king." Henry then turned against Robert's castles in the north. Against Blyth he marched himself, but on his approach he was met by the townsmen who received him as their "natural lord." To the Bishop of Lincoln he gave orders to besiege Tickhill castle, while he advanced towards the west, where lay Robert's chief possessions and greatest strength.
In his Shrewsbury earldom Robert had been preparing himself for the final struggle with the king ever since he had escaped his trial in the court. He counted upon the help of his two brothers, whose possessions were also in those parts, Arnulf of Pembroke, and Roger called the Poitevin, who had possession of Lancaster. The Welsh princes also stood ready, as their countrymen stood for centuries afterwards, to combine with any party of rebellious barons in England, and their assistance proved of as little real value then as later. With these allies and the help of Arnulf he laid waste a part of Staffordshire before Henry's arrival, the Welsh carrying off their plunder, including some prisoners. Robert's chief dependence, however, must have been upon his two very strong castles of Bridgenorth and Shrewsbury, both of which had been strengthened and provisioned with care for a stubborn resistance.
Henry's first attack with what seems to have been a large force was on Bridgenorth castle. Robert had himself chosen to await the king's attack in Shrewsbury, and had left three of his vassals in charge of Bridgenorth, with a body of mercenaries, who often proved, notwithstanding the oaths of vassals, the most faithful troops of feudal days. He had hoped that his Welsh friends would be able to interfere seriously with Henry's siege operations, but in this he was disappointed. The king's offers proved larger than his, at least to one of the princes, and no help came from that quarter. One striking incident of this siege, though recorded by Orderic Vitalis only, is so characteristic of the situation in England, at least of that which had just preceded the rebellion of Robert, and bears so great an appearance of truth, that it deserves notice. The barons of England who were with the king began to fear that if he were allowed to drive so powerful an earl as Robert of Bellême to his ruin the rest of their order would be henceforth at his mercy, and no more than weak "maid-servants" in his sight. Accordingly, after consulting among themselves, they made a formal attempt to induce the king to grant terms to Robert. In the midst of an argument which the king seems to have been obliged to treat with consideration, the shouts of 3000 country soldiers stationed on a hill near by made themselves heard, warning Henry not to trust to "these traitors," and promising him their faithful assistance. Encouraged by this support, the king rejected the advice of the barons.
The siege of Bridgenorth lasted three weeks. At the end of that time, Henry threatened to hang all whom he should capture, unless the castle were surrendered in three days; and despite the resistance of Robert's mercenaries, the terms he offered were accepted. Henry immediately sent out his forces to clear the difficult way to Shrewsbury, where Robert, having learned of the fall of Bridgenorth, was awaiting the issue, uncertain what to do. One attempt he made to obtain for himself conditions of submission, but met with a flat refusal. Unconditional surrender was all that Henry would listen to. Finally, as the king approached, he went out to meet him, confessed himself a traitor and beaten, and gave up the keys of the town. Henry used his victory to the uttermost. Personal safety was granted to the earl, and he was allowed to depart to his Norman possessions with horses and arms, but this was all that was allowed him. His vast possessions in England were wholly confiscated; not a manor was left him. His brothers soon afterwards fell under the same fate, and the most powerful and most dangerous Norman house in England was utterly ruined. For the king this result was not merely the fall of an enemy who might well be feared, and the acquisition of great estates with which to reward his friends; it was a lesson of the greatest value to the Norman baronage. Orderic Vitalis, who gives us the fullest details of these events states this result in words which cannot be improved upon: "And so, after Robert's flight, the kingdom of Albion was quiet in peace, and King Henry reigned prosperously three and thirty years, during which no man in England dared to rebel or to hold any castle against him."