Disappointed as it was, the Parliament with singular self-restraint turned to other modes of bringing about its purpose. The offer of the crown had been coupled with the condition of accepting a constitution which was a modification of the Instrument of Government adopted by the Parliament of 1654, and this constitution Cromwell emphatically approved. " The things provided by this Act of Government," he owned, " do secure the liberties of the people of God as they never before have had them." With a change of the title of King into that of Protector, the Act of Government now became law; and the solemn inauguration of the Protector by the Parliament was a practical acknowledgment on the part of Cromwell of the illegality of his former rule. In the name of the Commons the Speaker invested him with a mantle of State, placed the sceptre in his hand, and girt the sword of justice by his side. By the new Act of Government Cromwell was allowed to name his own successor, but in all after cases the office was to be an elective one. In every other respect the forms of the older Constitution were carefully restored.

Parliament was again to consist of two Houses, the seventy members of "the other House" being named by the Protector. The Commons regained their old right of exclusively deciding on the qualification of their members. Parliamentary restrictions were imposed on the choice of members of the Council, and officers of State or of the army. A fixed revenue was voted to the Protector, and it was provided that no moneys should be raised but by assent of Parliament. Liberty of worship was secured for all but Papists, Prelatists, Socinians, or those who denied the inspiration of the Scriptures; and liberty of conscience was secured for all.

The adjournment of the House after his inauguration left Cromwell at the height of his power. He seemed at last to have placed his government on a legal and national basis. The ill-success of his earlier operations abroad was forgotten in a blaze of glory. On the eve of the Parliament's assembly one of Blake's captains had managed to intercept a part of the Spanish treasure fleet. At the close of 1656 the Protector seemed to have found the means of realizing his schemes for rekindling the religious war throughout Europe in a quarrel between the Duke of Savoy and his Protestant subjects in the valleys of Piedmont. A ruthless massacre of these Vaudois by the Duke's troops roused deep resentment throughout England, a resentment which still breathes in the noblest of Milton's sonnets. While the poet called on God to avenge his "slaughtered saints, whose bones lie scattered on the Alpine mountains cold," Cromwell was already busy with the work of earthly vengeance. An English envoy appeared at the Duke's court with haughty demands of redress.

Their refusal would have been followed by instant war, for the Protestant Cantons of Switzerland were bribed into promising a force of ten thousand men for an attack on Savoy. The plan was foiled by the cool diplomacy of Mazarin, who forced the Duke to grant Cromwell's demands; but the apparent success of the Protector raised his reputation at home and abroad. The spring of 1657 saw the greatest as it was the last of the triumphs of Blake. He found the Spanish Plate fleet guarded by galleons in the strongly-armed harbour of Santa Cruz; he forced an entrance into the harbour and burnt or sank every ship within it. Triumphs at sea were followed by a triumph on land. Cromwell's demand of Dunkirk, which had long stood in the way of any acceptance of his offers of aid, was at last conceded; and a detachment of the Puritan army joined the French troops who were attacking Flanders under the command of Turenne. Their valour and discipline were shown by the part they took in the capture of Mardyke; and still more by the victory of the Dunes, a victory which forced' the Flemish towns to open their gates to the French, and gave Dunkirk to Cromwell.

Never had the fame of an English ruler stood higher; but in the midst of his glory the hand of death was falling on the Protector. He had long been weary of his task. "God knows," he had burst out to the Parliament a year before, "I would have been glad to have lived under my woodside, and to have kept a flock of sheep, rather than to have undertaken this government." And now to the weariness of powei was added the weakness and feverish impatience of disease. Vigorous and energetic as his life had seemed, his health was by no means as strong as his will; he had been struck down by intermittent fever in the midst of his triumphs both in Scotland and in Ireland, and during the past year he had suffered from repeated attacks of it. "I have some infirmities upon me," he owned twice over in his speech at the re-opening of the Parliament after an adjournment of six months; and his feverish irritability was quickened by the public danger. No supplies had been voted, and the pay of the army was heavily in arrear, while its temper grew more and more sullen at the appearance of the new Constitution and the re-awakening of the royalist intrigues.

Under the terms of the new Constitution the members excluded in the preceding year took their places again in the House. The mood of the nation was reflected in the captious and quarrelsome tone of the Commons. They still delayed the grant of supplies. Meanwhile a hastyact of the Protector in giving to his nominees in "the other House," as the new second chamber he had devised was called, the title of "Lords," kindled a strife between the two Houses which was busily fanned by Haselrig and other opponents of the Government. It was contended that the "other House" had under the new Constitution simply judicial and not legislative powers. Such a contention struck at Cromwell's work of restoring the old political forms of English life; and the reappearance of Parliamentary strife threw him at last, says an observer at his court, "into a rage and passion like unto madness." What gave weight to it was the growing strength of the royalist party, and its preparations for a coming rising. Charles himself with a large body of Spanish troops drew to the coast of Flanders to take advantage of it. His hopes were above all encouraged by the strife in the Commons, and their manifest dislike of the system of the Protectorate. It was this that drove Cromwell to action.