Essex reacted by making a surprise attack on the Royalist lines at dawn, capturing several pieces of high ground and leaving Charles on the back foot. A series of Royalist attacks led to large number of casualties and the slow retreat of Essex's force, which was driven from the central hill and almost encircled; Essex succeeded in rallying his infantry, however, and pushed forward in a counter-attack. The slowing of this counter-attack in the face of the Royalist cavalry forced Essex to send for reinforcements, who, while marching to him, were attacked and forced to retreat. This left a hole in the Parliamentarian line, dividing the army into two wings through which the Royalists hoped to pass, splitting the Parliamentarians and allowing Charles's troops to encircle and defeat the enemy. I