Counties of England
Having relieved the siege at York by out manoeuvering the Parliamentary Army, Prince Rupert wanted to engage Parliament's Allied Army. Rupert believed (controversially) that he had orders from the King to do so. The Parliamentary backed Allied Army of the Eastern Association, local Yorkshire forces along with the Scots under the Earl of Levin accommodated him between York and Knaresborough. Rupert was outnumbered, especially, because he could not get the siege-relieved forces at York to get the lead out until the last minute. The Marquess of Newcastle, who had held York through the siege, was against offering battle at Marston Moor, going so far as to remind Rupert of one of his past failures due to hasty decisions. Rupert prevailed, but even with the mainly infantry forces from York, Rupert mustered only 18,000 to the Allied Army's 28,000.