If men who have engaged in vast designs could ever promise themselves repose, William, after so many victories, and so many political regulations to secure the fruit of them, might now flatter himself with some hope of quiet.  But disturbances were preparing for his old age from a new quarter, from whence they were less expected and less tolerable,—­from the Normans, his companions in victory, and from his family, which he found not less difficulty in governing than his kingdom.  Nothing but his absence from England was wanting to make the flame blaze out.  The numberless petty pretensions which the petty lords his neighbors on the continent had on each other and on William, together with their restless disposition and the intrigues of the French court, kept alive a constant dissension, which made the king’s presence on the continent frequently necessary.  The Duke of Anjou had at this time actually invaded his dominions.  He was obliged to pass over into Normandy with an army of fifty thousand men.  William, who had conquered England by the assistance of the princes on the continent, now turned against them the arms of the English, who served him with bravery and fidelity; and by their means he soon silenced all opposition, and concluded the terms of an advantageous peace.  In the mean time his Norman subjects in England, inconstant, warlike, independent, fierce by nature, fiercer by their conquest, could scarcely brook that subordination in which their safety consisted.  Upon some frivolous pretences, chiefly personal disgusts,[75] a most dangerous conspiracy was formed:  the principal men among the Normans were engaged in it; and foreign correspondence was not wanting.  Though this conspiracy was chiefly formed and carried on by the Normans, they knew so well the use which William on this occasion would not fail to make of his English subjects, that they endeavored, as far as was consistent with secrecy, to engage several of that nation, and above all, the Earl Waltheof, as the first in rank and reputation among his countrymen.  Waltheof, thinking it base to engage in any cause but that of his country against his benefactor, unveils the whole design to Lanfranc, who immediately took measures for securing the chief conspirators.  He dispatched messengers to inform the king of his danger, who returned without delay at the head of his forces, and by his presence, and his usual bold activity, dispersed at once the vapors of this conspiracy.  The heads were punished.  The rest, left under the shade of a dubious mercy, were awed into obedience.  His glory was, however, sullied by his putting to death Waltheof, who had discovered the conspiracy; but he thought the desire the rebels had shown of engaging him in their designs demonstrated sufficiently that Waltheof still retained a dangerous power.  For as the years, so the suspicions, of this politic prince increased,—­at whose time of life generosity begins to appear no more than a splendid weakness.