The need of the Parliament was all the greater because for the campaign of 1645 their Scottish auxiliaries were practically not available. Late in the previous summer Montrose had succeeded in inducing a great part of the Highlands to take up arms for the king, and in a series of short campaigns, continued contrary to the usual practice of that age through the winter, had inflicted so many blows on the king's enemies all over Scotland that Leven's army was much wanted at home. Rupert, who was in the Severn region, urged his uncle to join him with all available troops, and make a push northwards, so as to defeat or drive away Leven's much diminished forces, and restore the royalist cause in the north of England, before the New Model army was ready. But for a brilliant dash made by Cromwell, who at the head of 1500 cavalry swept right round Oxford, defeating one detachment after another, and clearing the neighbourhood of all draught horses, there might have been time to achieve much. The delay thus caused prevented Charles from taking the field for some little time: but the Parliament went far towards neutralising this advantage by instructing Fairfax to go into Somerset and relieve Taunton, the most strongly Puritan town of the west, which was in great straits. Hearing that the king had called to Oxford some of the royalist troops in the west, they recalled Fairfax, too late to prevent the king marching where he pleased. They followed up this waste of time, which was not altogether their fault, by the error of bidding Fairfax besiege Oxford, where the king was not: it ought to have been sufficiently plain that to defeat the king's army in the field was the one paramount object. The king however, instead of either going northwards in earnest, which might have achieved something, or gathering every available man to face Fairfax, which would at any rate have brought matters boldly to a crisis, pushed across to Leicester, which he stormed after a few days' siege. Here he heard that Oxford was badly straitened for provisions, and must surrender unless soon relieved. Nothing can more strongly mark the incompetence of the king and his officers to administer, however they might fight, than his having left his head-quarters on a vague campaign, without having satisfied himself that the city was adequately provisioned to stand the siege which he knew was impending. There was nothing for it but to turn back towards Oxford. At Daventry the king learned that Fairfax had abandoned the siege; and he accordingly halted, not venturing to go northwards again until he knew that Oxford was properly supplied.