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]