The death of Eustace, Stephen’s son, in August, 1153, paved the way to an arrangement between the rivals. Stephen was to remain King, and Henry became his acknowledged successor. William, Stephen’s surviving son, was to retain the Warenne castles and estates, which included Ryegate, of which traces remain; Castle-Acre, with its mound and other earthworks, placed within a Roman encampment; Castle-Rising, one of the least injured and most remarkable Norman keeps in England; Lewes, with its double mound and strong natural position; and Coningsburgh, an English site of excessive strength, though not then as yet celebrated for its noble tower. He also had the castles of Wirmegay and Bungay, Norwich, and the castle and honour of Pevensey. It was also agreed that the garrisons of the royal castles generally should swear allegiance to Henry and to Stephen; and the castellans of Lincoln, London, Oxford, Southampton, and Windsor gave hostages that on Stephen’s death they would give them over to Henry. It was also agreed at a conference at Dunstable in 1154, that all castles built since the death of Henry I. should be destroyed (a clause which may be taken to show that no absolutely new castles of very great importance had been built by Matilda or Stephen); and that all mercenary troops should be sent back to their own countries. The office of sheriff, as representing the crown in the counties, was to be strengthened. Stephen died in October, 1154, and his rival ascended the throne as Henry II. without opposition. CHAPTER V. THE POLITICAL INFLUENCE OF CASTLES IN THE REIGN OF HENRY II. Henry II. was a great builder, and especially of military works. “In muris, in propugnaculis, in munitionibus, in fossatis, ... nullus subtilior, nullus magnificentior, invenitur.” This, however, does not so much refer to new castles, of which he built but few, as to the completion or addition of new keeps to the old ones, such, for example, as Dover.