With the destruction of Duke Robert’s fleet, the reduction of Pevensey and Rochester, and the expulsion of Odo of Bayeux from England, the force of the rebellion had been broken. Whatever plans the duke may have had to follow with a greater fleet were perforce abandoned. Through his own weakness and procrastination, coupled with the vigor and resourcefulness of William Rufus and the loyalty of the native English, the attempt to place Robert Curthose upon the throne of England, at one time so promising, had ended in utter failure.

But Robert’s failure did not end the hostility between the two brothers. No peace negotiations intervened. William Rufus continued to nurse his indignation and to thirst for vengeance. He professed to fear some further mischief from the duke.[53] Robert, too, remained suspicious and apprehensive. Prince Henry, learning of the fall of Rochester, and eager to conciliate the victor, had hastened across the Channel to visit the king and crave from him “the lands of his mother” to which he laid claim.[54] The duke regarded this move with little favor; and when, soon after,[55] Henry had accomplished his mission and was returning to Normandy in company with Robert of Bellême, who had also been reconciled with William Rufus, the duke had him seized at the landing and placed in custody. Malicious enemies, we are told, had poisoned the duke’s mind with the belief that Henry and Robert of Bellême had not only made their peace with the king, but had entered into a sworn agreement to his own hurt.[56] Henry was released from prison some six months later, at the solicitation of the Norman barons,[57] and the incident is not, perhaps, of great importance—for, if Henry and the king had arrived at any understanding, it must have been of short duration—yet it serves to illustrate the strained relations which continued to exist between Robert Curthose and William Rufus.

Meanwhile, the king, at last secure in his possession of the English throne, began to develop plans for taking vengeance upon the duke. If we can rely upon the unsupported statement of Ordericus Vitalis in such a matter, he held a formal assembly of his barons at Winchester, apparently in 1089,[58] and laid before them proposals for an attack upon Normandy. He harangued the assembled magnates upon the faithless conduct of his brother and upon the state of unchecked anarchy into which he had allowed his duchy to fall. The whole country, he declared, had become a prey to thieves and robbers, and the lamentations of the clergy had reached him from beyond the sea. It behooved him, therefore, as the son of his father, to send to Normandy for the succor of holy church, for the protection of widows and orphans, and for the just punishment of plunderers and assassins. Upon being asked their advice, the assembled nobles promptly approved the king’s project.[59] Perhaps some of the quondam rebels reasoned that, since the two realms could not be reunited under the weak and pliable Robert, it would still be worth their while to attempt to bring about the desired union under his more masterful brother.[60]

The king’s plan evidently did not involve immediate open war upon Robert Curthose. It was not the way of William Rufus to attempt upon the field of battle that which might more expeditiously be accomplished through diplomacy. This was a form of attack which the impoverished duke was little qualified to combat. Choosing as the field of his activities the Norman lands lying north and east of the Seine, William Rufus began by winning over by bribery the garrison of Saint-Valery at the mouth of the Somme, thus gaining a strong castle and a commodious seaport in a position most advantageously located for the further prosecution of his design. It must have been at about the same time that Stephen of Aumale yielded to the same golden argument, and opened the gates of his stronghold to the soldiers of King William. From these convenient bases plundering raids were then carried into the surrounding country.[61] Soon the contagion spread farther. Gerard of Gournay placed his castles of Gournay, La Ferté-en-Bray, and Gaillefontaine at the disposal of the king, and actively devoted himself to the promotion of the English cause among his neighbors. His example was promptly followed by Robert of Eu and Walter Giffard, lord of Longueville, and by Ralph of Mortemer. In short, by an effective blending of bribery and diplomacy, William Rufus had succeeded in detaching the greater part of the Norman nobles dwelling upon the right bank of the Seine from their allegiance to the duke.[62]

The single notable exception appears to have been Helias of Saint-Saëns, to whom Robert had given his illegitimate daughter, and with her the castles of Arques and Bures and their appurtenant lands as a marriage portion. Firmly establishing his son-in-law at Saint-Saëns, Arques, and Bures, the duke intended that he should stand as a counterpoise to the rapidly growing English influence east of the Seine.[63] And his expectations were not disappointed. Through every adversity, Helias of Saint-Saëns remained staunchly loyal to the cause of Robert Curthose and of his son, long after the final triumph of Henry I at Tinchebray.

Of other measures taken by the duke to combat the insidious aggression of his more resourceful rival, we have only the most fragmentary knowledge. From one of Robert’s charters, it appears that he besieged and captured the castle of Eu in 1089.[64] This, it seems not improbable, was one of his early and successful efforts against the Norman traitors and their English ally. We know, too, that in his extreme need he appealed to his overlord, the king of France. Yet here again our information is discouragingly fragmentary. Of the relations between the duke and his overlord after the death of William the Conqueror we know nothing except that on 24 April 1089 Robert was at Vernon on the Seine frontier, engaged in some sort of hostile enterprise against France.[65] Certain it is, however, that before the close of this year he had sought and obtained the aid of King Philip against his Anglo-Norman enemies in the lands east of the Seine.[66] Together they laid siege to La Ferté-en-Bray,[67] the castle of Gerard of Gournay. But again the golden diplomacy of William Rufus proved more than a match for the vanishing resources of the duke. “No small quantity of money having been transmitted secretly to King Philip,” he was readily induced to abandon the siege and return home.[68]

In 1090 difficulties continued to multiply around Duke Robert. In the city of Rouen itself William Rufus had contrived through bribery to gain a following, and had set himself to promote civic discord as a means of undermining the duke’s authority.[69] In November 1090 a factional conflict broke out in Rouen between two parties of the burghers, the Pilatenses and Calloenses. Of the latter we know no more than that they were the supporters of the duke and that they were the weaker of the two factions.[70] The Pilatenses were ably led by a certain Conan, son of Gilbert Pilatus, described as the wealthiest citizen of Rouen. His great riches enabled him to maintain a large household of retainers in opposition to the duke and to draw into his faction the greater part of the citizens. As a further resource, Conan had covenanted with William Rufus to deliver up to him the city. An insurrection was planned to take place on 3 November; and at the appointed hour the king’s hirelings were to come from Gournay and other neighboring fortresses to support the rising. Some of the king’s adherents had already secretly been brought within the walls, ready to join the rebels at the appointed moment.[71]

The duke learned late of the events that were impending and had barely time to call up reënforcements. Hasty summonses were sent to William of Évreux, Robert of Bellême, William of Breteuil, and Gilbert of Laigle. More important still, Prince Henry was induced to forget past wrongs and come to the duke’s assistance in this hour of need. These measures were taken barely in time to avert a disaster. Henry, apparently, was already within the city before the outbreak; but as Gilbert of Laigle with a troop of horse galloped across the bridge over the Seine and entered Rouen from the south, Reginald of Warenne with three hundred supporters of William Rufus was already battering at the western gate. Meanwhile, within the city the insurrection had broken out amid scenes of wild confusion. Robert and Henry issued from the citadel and began to attack the rebels upon front and rear. Robert was personally brave and a sturdy fighter, and on later occasions he proved himself an excellent leader in emergencies. But in the wild confusion and uncertainties of the Rouen insurrection, his friends became alarmed lest some serious mishap should befall him, and persuaded him to retire to a place of safety and not expose himself to such grave perils until the issue of the conflict should be decided. Accordingly, he withdrew by the eastern gate into the Faubourg Malpalu, and, there taking a boat across the Seine to Émendreville, he found shelter in the priory of Notre-Dame-du-Pré.[72] Meanwhile, within the city, Henry and Gilbert of Laigle and their supporters put down the insurrection with a great slaughter of the inhabitants. Conan and many other rebels were captured, and the hirelings of William Rufus were obliged to withdraw in confusion and seek the shelter of a neighboring wood, until under the cover of darkness they were able to make good their escape. With the triumph of his forces, the duke returned to the city, and, with his habitual mildness, was for throwing Conan into a dungeon and showing clemency to the rest of the rebels. But his barons had other views, and insisted upon taking a savage vengeance upon the burghers who had been involved in the treason. William, son of Ansger, one of the richest men in the city, was led away into captivity by William of Breteuil and held for a ransom of 3000 livres. As for Conan, the archtraitor, Prince Henry craved leave of the duke to dispose of him in his own way. Taking him up to the upper story of the tower of Rouen, where a window commanded a view of the surrounding country, he called upon the wretch to view the beauties of the landscape as it stretched away across the Seine; and then, swearing by the soul of his mother that a traitor should not be admitted to ransom, he thrust him backwards through the window. The place, says Ordericus Vitalis, is known as Conan’s Leap “unto this day.”[73]