The king himself was meanwhile already carrying into effect, with his eyes fully open to the consequences, a project which brought him into collision with the highest ecclesiastical authority in Normandy. Of all the approaches to the Norman capital the most important was the broad valley through which the Seine winds its course from Paris across the old battle-ground of the Vexin to the heart of the duchy, while on either side of this water-way roads from north and east and south converge to meet beneath the walls of Rouen. Philip was now master of this valley and its surroundings up to a distance of about twelve miles from the city. The key of the position, however, was neither in his hands nor in Richard’s, but in those of the archbishop of Rouen; it was Andely. The town of Andely stood at the meeting-point of several roads, on the north side of a stream called the Gambon, in a valley opening from the eastward upon the Seine through the chalk cliffs on its right bank, near the middle of a great curve to the northward in its course between Gaillon and Louviers. To the west of Andely the Gambon and another rivulet became merged in a lake or mere whence they issued again to fall into the great river by two distinct openings separated by a tract of marshland, at the south-east corner of which stood the toll-house. Nearly opposite the mouth of each streamlet was an island in the Seine; the more northerly and larger one was known as the Isle of Andely. The valley was sheltered on its southern side by a thickly wooded plateau extending several miles to a point nearly opposite Gaillon, and called the Forest of Andely. Opposite the toll-house, at the angle formed by the junction of the Gambon with the Seine, this plateau terminated abruptly in a mass of limestone rock three hundred feet high, with its western face, nearly perpendicular, looking down upon the Seine, its northern front, almost as steep, towering above the Gambon, and only a narrow neck of rocky ground at its south-eastern corner connecting it with the plateau, from which its other sides were separated by deep ravines. The military possibilities of such a position were obvious, and would doubtless have been utilized long before they attracted the rival kings if Andely had been a lay fief. For Philip it would have made an ideal base for attack upon Rouen; Richard saw in it a matchless site for the construction of an almost impassable barrier between Rouen and Paris. Philip had tried in vain to win it by diplomacy. Richard took advantage of a temporary absence of the archbishop from Normandy to seize the Isle of Andely and begin to build a fort upon it. Walter protested strongly, but in vain; Richard’s sole answer was to take possession of the low ground enclosed between the three rivers and the lake and begin to cover it with the foundations of a walled town with trenches and barbicans on every side. The primate then told the