Robert of Belleme had lost too much in England to rest satisfied with the position into which he had been forced. He was of too stormy a disposition himself to settle down to a quiet life on his Norman lands. Duke Robert had attacked one of his castles, while Henry was making war upon him in England, but, as was usual in his case, totally failed; but it was easy to take vengeance upon the duke, and he was the first to suffer for the misfortunes of the lord of Belleme. All that part of Normandy within reach of Robert was laid waste; churches and monasteries even, in which men had taken refuge, were burned with the fugitives. Almost all Normandy joined in planning resistance. The historian, Orderic, living in the duchy, speaks almost as if general government had disappeared, and the country were a confederation of local states. But all plans were in vain, because a "sane head" was lacking. Duke Robert was totally defeated, and obliged to make important concessions to Robert of Belleme. At last Henry, moved by the complaints which continued to come to him from churchmen and barons of Normandy, some of whom came over to England in person, as well as from his own subjects, whose Norman lands could not be protected, resolved himself to cross to Normandy. This he did in the autumn of 1104, and visited Domfront and other towns which belonged to him. There he was joined by almost all the leading barons of Normandy, who were, indeed, his vassals in England, but who meant more than this by coming to him at this time.

The expedition, however, was not an invasion. Henry did not intend to make war upon his brother or upon Robert of Belleme. It was his intention rather to serve notice on all parties that he was deeply interested in the affairs of Normandy and that anarchy must end. To his brother Robert he read a long lecture, filled with many counts of his misconduct, both to himself personally and in the government of the duchy. Robert feared worse things than this, and that he might turn away his brother's wrath, ceded to him the county of Evreux, with the homage of its count, William, one of the most important possessions and barons of the duchy. Already in the year before Robert had been forced to surrender the pension Henry had promised him in the treaty which they had made after Robert's invasion. This was because of a rash visit he had paid to England without permission, at the request of William of Warenne, to intercede for the restoration of his earldom of Surrey. By these arrangements Robert was left almost without the means of living, but he was satisfied to escape so easily, for he feared above all to be deprived of the name of duke and the semblance of power. Before winter came on the king returned to England.

In this same year, following out what seems to have been the deliberate purpose of Henry to crush the great Norman houses, another of the most powerful barons of England was sent over to Normandy, to furnish in the end a strong reinforcement to Robert of Belleme, a man of the same stamp as himself, namely William of Mortain, Earl of Cornwall, the king's own cousin. At the time of Henry's earliest troubles with his brother Robert, William had demanded the inheritance of their uncle Odo, the earldom of Kent. The king had delayed his answer until the danger was over, had then refused the request, and shortly after had begun to attack the earl by suits at law. This drove him to Normandy and into the party of the king's open enemies. On Henry's departure, Robert with the help of William began again his ravaging of the land of his enemies, with all the former horrors of fire and slaughter. The peasants suffered with the rest, and many of them fled the country with their wives and children.

If order was to be restored in Normandy and property again to become secure, it was clear that more thorough-going measures than those of Henry's first expedition must be adopted. These he was now determined to take, and in the last week of Lent, 1105, he landed at Barfleur, and within a few days stormed and destroyed Bayeux, which had refused to surrender, and forced Caen to open its gates. Though this formed the extent of his military operations in this campaign, a much larger portion of Normandy virtually became subject to him through the voluntary action of the barons. And in a quite different way his visit to Normandy was of decisive influence in the history of Henry and of England. As the necessity of taking complete possession of the duchy, in order to secure peace, became clear to Henry, or perhaps we should say as the vision of Normandy entirely occupied and subject to his rule rose before his mind, the conflict with Anselm in which he was involved began to assume a new aspect. As an incident in the government of a kingdom of which he was completely master, it was one thing; as having a possible bearing on the success with which he could conquer and incorporate with his dominions another state, it was quite another.

Anselm had gone to Rome toward the end of the summer of 1103. There he had found everything as he had anticipated. The argument of Henry's representative that England would be lost to the papacy if this concession were not granted, was of no avail. The pope stood firmly by the decrees against investiture. But Henry's ambassador was charged with a mission to Anselm, as well as to the pope; and at Lyons, on the journey back, the archbishop was told that his return to England would be very welcome to the king when he was ready to perform all duties to the king as other archbishops of Canterbury had done them. The meaning of this message was clear. By this stroke of policy, Henry had exiled Anselm, with none of the excitement or outcry which would have been occasioned by his violent expulsion from the kingdom.