In the mind of Lewis peace meant a series of outrages on the powers around him; but every outrage helped the cool and silent adversary who was looking on from the Hague in his task of building up that Great Alliance of all Europe from which alone he looked for any effectual check to the ambition of France. The experience of the last war had taught William that of such an alliance England must form a part, and the efforts of the Prince ever since the peace had been directed to secure her co-operation. A reconciliation of the king with his Parliament was an indispensable step towards freeing Charles from his dependence on France, and it was such a reconciliation that William at first strove to bring about; but he was for a long time foiled by the steadiness with which Charles clung to the power whose aid was needful to carry out the schemes which he was contemplating. The change of policy, however, which followed on the fall of the Cabal and the entry of Danby into power raised new hopes in William's mind, and his marriage with Mary dealt Lewis what proved to be a fatal blow. James was without a son, and the marriage with Mary would at any rate ensure William the aid of England in his great enterprise on his father-in-law's death. But it was impossible to wait for that event, and though the Prince used his new position to bring Charles round to a decided policy his efforts remained fruitless. The storm of the Popish Plot complicated his position. In the earlier stages of the Exclusion Bill, when the Parliament seemed resolved simply to pass over James and to seat Mary at once on the throne after her uncle's death, William stood apart from the struggle, doubtful of its issue though prepared to accept the good luck if it came to him. But the fatal error of Shaftesbury in advancing the claims of Monmouth forced him into action. To preserve his wife's right of succession with all the great issues which were to come of it, as well as to secure his own, no other course was left than to adopt the cause of the Duke of York. Charles too seemed at last willing to purchase the support of the Prince in England by a frank adhesion to his policy abroad. He protested against the encroachments which Lewis was making in Germany. He promised aid to Holland in case of attack. He listened with favour to William's proposal of a general alliance of the European powers, and opened negotiations for that purpose with Brandenburg and Spain. William indeed believed that the one step now needed to bring England to his side in the coming struggle with Lewis was a reconciliation between Charles and the Parliament grounded on the plan for providing Protestant securities which Charles was ready again to bring forward. [Sidenote: William and the Exclusion.]