And even in the royalist Fylde the Earl's enemies were already active. Some of the Commissioners of the Militia collected a few soldiers, and surprised the crews of Derby's ships at Preesall, took them prisoners and seized the ships. The prisoners were taken first to Preston, and then on an alarm of the royalists' march thither, to York, narrowly escaping a rescue party under Tyldesley. The chief of them, Captain Cotterell, who had done much service for the royalists at sea, was tried and executed.[230] Moreover, Colonel Robert Lilburne had been ordered to Lancashire with his regiment, and was now marching in hot haste. From Warrington the Earl of Derby moved northwards to Preston, and remained there for some days. He issued warrants for raising troops in the Fylde, and arranged for musters at Singleton and at Kirkham on August 25th; but these musters were never held. Lilburne, having made a forced march from Cheshire, reached Wigan on August 21st, thinking to have surprised the royalists; but they had retreated to Chorley. Next day (Friday, August 22nd) he advanced to Preston, and in the night sent 40 horse to make a surprise attack. Colonel Vere was wounded in the skirmish and apparently took no part in the further fighting. The royalists had now increased their numbers to about 600 horse and 900 foot, and held a rendezvous at Preston on Saturday, August 23rd. Lilburne was not anxious to force on an engagement, as he had no infantry with him, and his men were tired with their long marches from Cheshire. Cromwell's own regiment of foot under Major-General Worsley were following him as fast as possible, and he resolved to wait for this reinforcement. On the same day the royalists delivered a surprise attack on their own account. Lilburne had now encamped at Brindle, four miles from Preston, and the royalists were informed by a secret enemy "they being all enemies hereabouts" that the horses were turned loose and the men off their guard. A party of about 20 horse, mostly gentlemen's sons from the Fylde and their servants, rode out of Preston for the adventure, and guided by byways reached the Parliamentarian camp unperceived. Lilburne's troopers were lying on the grass by their saddles, half asleep in the summer afternoon, with their horses grazing near by in the fields between Brindle and Preston. Suddenly the royalists, who had evaded the guard in the lane below burst out upon them. For a few moments all was confusion; but "the finest soldiers in Europe" were more than a match for a few hot-headed youths, even caught thus at a disadvantage. Recovering their horses they fell upon the assailants and pursued them as far as Ribble Bridge; and all the royalists were either taken or slain, excepting one who escaped like Charles II. after Worcester, by climbing into a tree and hiding there until the following day. Among those killed were the sons of Mr. Butler of Rawcliffe and Mr. Hesketh of Maines Hall, near Poulton-le-Fylde.