The Battle of Preston was fought over two days in August 1648. After this battle, a defeated Charles I stood no chance of overthrowing Parliamentís power. The Battle of Preston allied a Scottish force with the Royalists who had also gathered in Scotland. By simply doing this, should Charles ever be captured again, he faced the real peril of being charged with treason. At the very least, no one in Parliament would trust him again.
In April 1648 a small force of Scots commanded by Marmaduke Langsdale had crossed the border and taken Berwick and Carlisle. On July 8th, a much larger force commanded by the Marquis of Hamilton marched into Carlisle. By mid-July, 12,000 men (8,000 Scots and 4,000 Royalists) looked poised to march south in support of Charles. However, there were delays in the Scottish advance and this allowed a Parliamentarian force led by General John Lambert to cross the Pennines east to west to confront the invaders. A force led by Oliver Cromwell helped him. Pembroke Castle had fallen to Cromwell on July 11th and freed up men to march north and support Lambert. They met at Wetherby.
However, they were confronted by a much larger force: Hamiltonís army numbered 20,000 men while Cromwell had 9,000 men of whom only 6,500 were experienced soldiers.
What Cromwell had on his side was discipline. In some respects the Scots had become a very undisciplined unit. Hamilton had allowed his army to spread itself over twenty miles Ė a distance far too great to allow for good communications between all parts in it. Without good communications, Hamilton had little ability to fully control his force. Hamiltonís cavalry was in the front while the infantry trailed behind. Therefore, each was unable to support the other. While Hamiltonís cavalry had the advantage of travelling by horse, the terrain in the area was not conducive to speedy travel and the rain that had been falling made the ground even more boggy than normal.
On August 17th Cromwell attacked the infantry in the rear of Hamiltonís greatly extended force.
The Battle of Preston was fought in boggy terrain and the skill and power of the New Model Army was severely restricted in such terrain as it relied very much on its cavalry. The battle was initially fought with little finesse as Cromwell used his horse to simply bludgeon the Scots into submission. He then turned on Hamiltonís main force, many of whom had based themselves actually in Preston. The fighting in Preston was bloody even by the standards of the English Civil War. It was now that it became clear to Hamilton that keeping his force spread out over such a large distance was a fatal flaw. Cromwell fought mainly foot soldiers. Hamilton had to get his horse to Preston but they were mainly in Wigan, some miles away. The fighting on August 17th at Preston cost the Scots 8,000 men Ė 4,000 killed and 4,000 captured. The battle continued on August 18th.
The night of August 17th/18th had been blighted by rain. The Scots who were still in the field were both wet and hungry, as many had not eaten properly for days. To make matters worse, a lot of their ammunition had become damp and unusable. On the 18th, about 4,000 Scots laid down their weapons at Warrington rather than fight a smaller Parliamentarian force. Men under the command of Hamilton marched south away from Preston. Hamiltonís plan was to march south and then back north away from Cromwellís men and back to Scotland. The plan had some credibility to it but Hamiltonís men were unwilling to follow him and he surrendered his forces at Uttoxeter to John Lambert. Hamilton himself was sent to Windsor.
The fighting during the Battle of Preston was particularly vicious and as a result of this those who had volunteered to fight for Hamilton and had been captured or surrendered were harshly treated. They were sent as virtual slaves to the plantations in Barbados and Virginia. Those conscripted into Hamiltonís army were sent home.
The loss of the Scots and the accompanying Royalists who had fought at Preston was a devastating blow for Charles. He now had no decent power base in England, Wales, Ireland or Scotland.