It may, perhaps, be doubted whether William Rufus seriously intended to exert himself to carry out the provisions of this treaty, except in so far as his own interests dictated; although William of Malmesbury affirms that the king and the duke in pursuance of their agreement immediately took in hand the preparation of an expedition against Maine, and were only turned back from it by the disconcerting action of their younger brother, Prince Henry.[93] The details of Henry’s movements after the death of the Conqueror are obscure and uncertain, though the main lines of his policy and conduct seem clear enough. His relations had not been uniformly harmonious with either of his brothers. As has already been pointed out, his early friendship with the duke and his acquisition of the Cotentin had been followed by a period of imprisonment.[94] Apparently, too, Duke Robert, after he had squandered the money which he had obtained from Henry in exchange for the Cotentin, had endeavored to dispossess the young prince of the lands he had granted him, and had only been prevented from so doing by a show of force.[95] It was only a temporary reconciliation which had gained for the duke the important services of Henry during the insurrection at Rouen in November 1090. Fresh misunderstandings soon followed, and Henry was again obliged to retire to his lands in the Cotentin,[96] where he gained the warm friendship of his father’s old vassals, Hugh of Avranches and Richard de Redvers, and devoted himself with energy to the strengthening of his castles at Avranches, Cherbourg, Coutances, and Gavray.[97] With William Rufus, too, he had a quarrel of long standing. The early hopes raised by his visit to the king after the fall of Rochester in 1088[98] had not been fulfilled. The English lands of Matilda to which he laid claim had been granted to Robert Fitz Hamon, and he had been able to obtain no redress.[99] It was even said that he had assisted the duke at Rouen out of a desire for vengeance upon the king.[100] Finally, the treaty of peace which William and Robert had recently concluded was manifestly aimed directly against him. They had planned between themselves for an exclusive partition of all the Conqueror’s dominions, and for a recovery of ducal authority at all points where it was being defied. That obviously meant, among other places, in the Cotentin; and the clauses ceding Mont-Saint-Michel and Cherbourg to William Rufus were not likely to remain a dead letter. Henry realized the menace and protested vigorously against the injustice of a plan to deprive him of all share in the dominions of his glorious father.[101] He collected troops wherever he could find them in Brittany or Normandy, reënforced the defences of Coutances and Avranches with feverish energy, and prepared for war.[102]