Although the government of the country was now virtually in the hands of the Independents and of the army, the state of affairs was extremely critical, and none other than Cromwell could have extricated the dominant party from the difficulties. In one quarter was an imprisoned and intriguing king in league with the Scots, while the royalist party was waiting for the first reverse to rise up again with new strength in various parts of the land. Indeed, there were several insurrections, which required all the vigor of Cromwell to suppress. The city of London, which held the purse-strings, was at heart Presbyterian, and was extremely dissatisfied with the course affairs were taking. Then, again, there was a large, headstrong, levelling, mutineer party in the army, which clamored for violent courses, which at that time would have ruined every thing. Finally, the Scotch parliament had voted to raise a force of forty thousand men, to invade England and rescue the king. Cromwell, before he could settle the peace of the country, must overcome all these difficulties. Who, but he, could have triumphed over so many obstacles, and such apparent anarchy?
The first thing Cromwell did was to restore order in England; and therefore he obtained leave to march against the rebels, who had arisen in various parts of the country. Scarcely were these subdued, before he heard of the advance of the Scottish army, under the Duke of Hamilton. A second civil war now commenced, and all parties witnessed the result with fearful anxiety.
The army of Hamilton was not as large as he had hoped. Still he had fifteen thousand men, and crossed the borders, while Cromwell was besieging Pembroke, in a distant part of the kingdom. But Pembroke soon surrendered; and Cromwell advanced, by rapid marches, against the Scottish army, more than twice as large as his own. The hostile forces met in Lancashire. Hamilton was successively defeated at Preston, Wigan, and Warrington. Hamilton was taken prisoner at Uttoxeter, August 25, 1648, and his invading army was completely annihilated.
Cromwell then resolved to invade, in his turn, Scotland itself, and, by a series of military actions, to give to the army a still greater ascendency. He was welcomed at Edinburgh by the Duke of Argyle, the head of an opposing faction, and was styled "the Preserver of Scotland." That country was indeed rent with most unhappy divisions, which Lieutenant-General Cromwell remedied in the best way he could; and then he rapidly retraced his steps, to compose greater difficulties at home. In his absence, the Presbyterians had rallied, and were again negotiating with the king on the Isle of Wight, while Cromwell was openly denounced in the House of Lords as ambitious, treacherous, and perfidious. Fairfax, his superior in command, but inferior in influence, was subduing the rebel royalists, who made a firm resistance at Colchester, and all the various parties were sending their remonstrances to parliament.