Early on 26 October, the combined Parliamentarian armies advanced to Clay Hill, a few miles east of Newbury, where they set up an artillery battery. Intermittent exchanges of cannon fire took place throughout the day. Essex had been taken ill, and Waller and Manchester decided that a frontal attack on Donnington Castle and Shaw House would be too costly. They opted instead to divide their forces. While Manchester demonstrated with 7,000 infantry against Shaw House, Waller took 12,000 men (including the infantry from the Earl of Essex's army, a brigade of the London Trained Bands and most of the cavalry) on a long march of around the Royalist position to fall on Speen from the west. It was intended that on hearing the opening cannonade from Waller's guns, Manchester would then put in a full-scale attack on Shaw House.