The moral advantage however rested with the king. Essex had learned that his troopers were no match for the Cavaliers, and his withdrawal to Warwick left open the road to the capital. Rupert pressed for an instant march on London, where the approach of the king's forces had roused utter panic. But the proposal found stubborn opponents among the moderate Royalists, who dreaded the complete triumph of Charles as much as his defeat; and their pressure forced the king to pause for a time at Oxford, where he was received with uproarious welcome. When the cowardice of its garrison delivered Reading to Rupert's horse, and his daring capture of Brentford in November drew the royal army in his support almost to the walls of the capital, the panic of the Londoners was already over, and the junction of their train-bands with the army of Essex forced Charles to fall back again on his old quarters. But though the Parliament rallied quickly from the blow of Edgehill, the war, as its area widened through the winter, went steadily for the king. The fortification of Oxford gave him a firm hold on the midland counties; while the balance of the two parties in the North was overthrown by the march of the Earl of Newcastle, with a force he had raised in Northumberland, upon York. Lord Fairfax, the Parliamentary leader in that county, was thrown back by Newcastle's attack on the manufacturing towns of the West Riding, where Puritanism found its stronghold; and the arrival of the queen in February 1643 with arms from Holland encouraged the royal army to push its scouts across the Trent, and threaten the eastern counties, which held firmly for the Parliament. The stress of the war was shown by the vigorous efforts of the Houses. Some negotiations which had gone on into the spring were broken off by the old demand that the king should return to his Parliament; London was fortified; and a tax of two millions a year was laid on the districts which adhered to the Parliamentary cause.
In the spring of 1643 Lord Essex, whose army had been freshly equipped, was ordered to advance upon Oxford. But though the king held himself ready to fall back on the West, the Earl shrank from again risking his raw army in an encounter. He confined himself to the recapture of Reading, and to a month of idle encampment round Brill. But while disease thinned his ranks and the Royalists beat up his quarters the war went more and more for the king. The inaction of Essex enabled Charles to send a part of his small force at Oxford to strengthen a Royalist rising in the West. Nowhere was the royal cause to take so brave or noble a form as among the Cornishmen. Cornwall stood apart from the general life of England: cut off from it not only by differences of blood and speech, but by the feudal tendencies of its people, who clung with a Celtic loyalty to their local chieftains, and suffered their fidelity to the Crown to determine their own. They had as yet done little more than keep the war out of their own county; but the march of a small Parliamentary force under Lord Stamford upon Launceston forced them into action. In May 1643 a little band of Cornishmen gathered round the chivalrous Sir Bevil Greenvil, "so destitute of provisions that the best officers had but a biscuit a day," and with only a handful of powder for the whole force; but, starving and outnumbered as they were, they scaled the steep rise of Stratton Hill, sword in hand, and drove Stamford back on Exeter with a loss of two thousand men, his ordnance and baggage-train. Sir Ralph Hopton, the best of the Royalist generals, took the command of their army as it advanced into Somerset, and drew the stress of the war into the West. Essex despatched a picked force under Sir William Waller to check their advance; but Somerset was already lost ere he reached Bath, and the Cornishmen stormed his strong position on Lansdowne Hill in the teeth of his guns. The stubborn fight robbed the victors of their leaders; Hopton was wounded, Greenvil slain, and with them fell the two heroes of the little army, Sir Nicholas Slanning and Sir John Trevanion, "both young, neither of them above eight-and-twenty, of entire friendship to one another, and to Sir Bevil Greenvil." Waller too, beaten as he was, hung on their weakened force as it moved for aid upon Oxford, and succeeded in cooping up the foot in Devizes. But in July the horse broke through his lines; and joining a force which Charles had sent to their relief, turned back, and dashed Waller's army to pieces in a fresh victory on Roundway Down.