Anselm left England early in November, 1097, not to return during the lifetime of William. If he had hoped, through the intervention of the pope, to weaken the hold of the king on the Church of England, and to be put in a position where he could carry out the reforms on which his heart was set, he was doomed to disappointment. After a stay of some months at Lyons, with his friend Archbishop Hugh, he went on to Rome, where he was treated with great ceremonial honour by the pope, but where he learned that the type of lofty and uncompromising independence which he himself represented was as rare in the capital of the Christian world as he had found it among the bishops of England. There, however, he learned a stricter doctrine on the subject of lay investitures, of appointments to ecclesiastical office by kings and princes, than he had yet held, so that when he finally returned to England he brought with him the germs of another bitter controversy with a king, with whom but for this he might have lived in peace.
In the same month with Anselm, William also crossed to Normandy, but about very different business. Hardly had he obtained possession of the duchy when he began to push the claims of the duke to bordering lands, to the French Vexin, and to the county of Maine, claims about which his brother had never seriously concerned himself and which, in one case, even his father had allowed to slumber for years. Robert had, indeed, asserted his claim to Maine after the death of his father, and had been accepted by the county; but a revolt had followed in 1190, the Norman rule had been thrown off, and after a few months Elias of La Fleche, a baron of Maine and a descendant of the old counts, had made himself count. He was a man of character and ability, and the peace which he established was practically undisturbed by Robert; but the second William had no mind to give up anything to which he could lay a claim. He demanded of the French king the surrender of the Vexin, and warned Elias, who had taken the cross, that the holy errand of the crusade would not protect his lands during his absence. War followed in both cases, simultaneous wars, full of the usual incidents, of the besieging of castles, the burning of towns, the laying waste of the open country; wars in which the ruin of his peasantry was almost the only way of coercing the lord. William's operations were almost all successful, but he died without accomplishing all that he had hoped for in either direction. In the Vexin he captured a series of castles, which brought him almost to Paris; in Maine he captured Le Mans, lost it again, and finally recovered its possession, but the southern part of the county and the castles of Elias there he never secured.
In the year 1098 Magnus, king of Norway, had appeared for a moment with a hostile fleet off the island of Anglesey. Some reason not certainly known had brought him round Scotland, perhaps to make an attack on Ireland. He was the grandson of the King Harold of Norway, who had invaded England on the eve of the Norman Conquest and perished in the battle of Stamford Bridge, and he had with him, it is said, a son of Harold of England: to him the idea of a new invasion of England would not seem strange. At any rate, after taking possession of the Isle of Man, he came to the help of the Welsh against the earls, Hugh of Chester and Hugh of Shrewsbury, who were beginning the conquest of Anglesey. The incident is noteworthy because, in the brief fighting which occurred, the Earl of Shrewsbury was slain. His death opened the way for the succession of his brother, Robert of Belleme, to the great English possessions of their father in Wales, Shropshire, and Surrey, to which he soon added by inheritance the large holdings of Roger of Bully in Yorkshire and elsewhere. These inheritances, when added to the lands, almost a principality in themselves, which he possessed in southern Normandy and just over the border in France, made him the most powerful vassal of the English king. In character he had inherited far more from his tyrannous and cruel mother, Mabel, daughter of William Talvas of Belleme, than from his more high-minded father, Roger of Montgomery, the companion of the Conqueror. As a vassal he was utterly untrustworthy, and he had become too powerful for his own safety or for that of the king.
Some minor events of these years should be recounted. In 1097 William had sent Edgar the atheling to Scotland with an army, King Donald had been overthrown, and Edgar's nephew, himself named Edgar, with the support of the English king, had been made king. In 1099 Ranulf Flambard received the reward of his faithful services, and was made Bishop of Durham, in some respects the most desirable bishopric in England. Greater prospects still of power and dominion were opened to William a few months before his death, by the proposition of the Duke of Aquitaine to pledge him his great duchy for a sum of money to pay the expenses of a crusade. To add to the lands he already ruled those between the Loire and the Garonne would be almost to create a new monarchy in France and to threaten more dangerously at this moment the future of the Capetian kingdom than did two generations later the actual union of these territories and more under the king of England.