By the close of the year Parliament began to realise that if the war were to be carried to a successful issue, some more effective force than mere trained bands must be called into existence. It accordingly voted that Essex's army should be fixed at a permanent establishment of ten thousand foot and four thousand horse with a regular rate of monthly pay. This was progress in the right direction, but in the disorder of the financial administration it was extremely doubtful whether the scheme would not be wrecked by its cost. Meanwhile the Scots had crossed the Tweed and fairly entered as partners with the Parliament in the rebellion. This new factor led to the formation of a Committee of Both Kingdoms for the subsequent conduct of the war, an important step towards unity of design and administration but clogged by one fatal defect, namely, that the military members--Essex, Manchester, Waller, and Cromwell--were all absent in the field, and that the direction of operations therefore fell entirely into the hands of civilians. A Committee was better than a whole House, and that was all that could be said, for the new directorate soon came into collision with its officers in the field. On the invasion of the Scots, Charles of necessity altered his plan of campaign and detached Rupert to the north, who marked the line of his advance in deeper than ordinary lines of desolation and bloodshed. The Parliamentary generals in the north, Fairfax and Manchester, were at the time engaged upon the siege of York. The Committee, scared by the terror of Rupert's march, ordered them to raise the siege and move southward to meet him. They flatly refused; and their persistence in their own design led to the greatest military success hitherto achieved by the Parliament, the victory of Marston Moor. [Sidenote: July 2.] Of no battle are contemporary accounts more difficult of reconciliation than those of Marston Moor, but the main features of the action are distinguishable and may be briefly set down. Both armies consisted of about twenty-three thousand men, and were drawn up in two lines, the infantry in the centre and the cavalry in the flanks. On the Royalist side Rupert, as was usual for the Commander-in-Chief, led the right wing,[162] five thousand horse in one hundred troops; his centre, fourteen thousand foot, was under Eythin, a veteran officer imported from Germany; his left, four thousand cavalry, was led by Goring. On the Parliamentary side Ferdinand, Lord Fairfax, commanded the right wing of horse, the first line consisting of English, the second of Scots; the centre was composed principally of Scottish infantry under old Alexander Leslie, Earl of Leven; the left wing of horse was commanded by Cromwell, his first line being composed of English, and the second of Scots under the leadership of David Leslie.