At the beginning of the Civil War, Parliament relied on soldiers recruited by large landowners who supported their cause. In February 1645, Parliament decided to form a new army of professional soldiers and amalgamated the three armies of William Waller, Earl of Essex and Earl of Manchester. This army of 22,000 men became known as the New Model Army. Its commander-in-chief was General Thomas Fairfax, while Oliver Cromwell was put in charge of its cavalry.
Members of the New Model Army received proper military training and by the time they went into battle they were very well-disciplined. In the past, people became officers because they came from powerful and wealthy families. In the New Model Army men were promoted when they showed themselves to be good soldiers. For the first time it became possible for working-class men to become army officers. Oliver Cromwell thought it was very important that soldiers in the New Model Army believed strongly in what they were fighting for. Where possible he recruited men who, like him, held strong Puritan views and the New Model Army went into battle singing psalms, convinced that God was on their side.
The New Model Army took part in its first major battle just outside the village of Naseby in Northamptonshire on 14 June 1645. The battle began when Prince Rupert led a charge against the left wing of the parliamentary cavalry which scattered and Rupert's men then gave chase.
While this was going on Cromwell launched an attack on the left wing of the royalist cavalry. This was also successful and the royalists that survived the initial charge fled from the battlefield. While some of Cromwell's cavalry gave chase, the majority were ordered to attack the now unprotected flanks of the infantry. Charles I was waiting with 1,200 men in reserve. Instead of ordering them forward to help his infantry he decided to retreat. Without support from the cavalry, the royalist infantry realised their task was impossible and surrendered.
By the time Prince Rupert's cavalry returned to the battlefield the fighting had ended. Rupert's cavalry horses were exhausted after their long chase and were not in a fit state to take on Cromwell's cavalry. Rupert had no option but to ride off in search of Charles I.
The battle was a disaster for the king. About 1,000 of his men had been killed, while another 4,500 of his most experienced men had been taken prisoner. The Parliamentary forces were also able to capture the Royalist baggage train that contained his complete stock of guns and ammunition.
The Battle of Naseby was the turning point in the war. After Naseby, Charles was never able to raise another army strong enough to defeat the parliamentary army in a major battle.
The officers of this army, as you may read, are such, as knew little of war, than our own unhappy wars had taught them, except some few, so as men could not contribute much to this work: indeed I may say this, they were better Christians than soldiers, and wiser in faith than in fighting, and could believe a victory sooner than contrive it; and yet I think they were as wise in the way of soldiery as the little time and experience they had could make them.
These officers, many of them with their soldiery, were much in prayer and reading scripture, an exercise that soldiers till of late have used bur little, and thus then went on and prospered: men conquer better as they are saints, than soldiers; and in the countries where they came, they left something of God as well as of Caesar behind them, something of piety as well as pay.
They were much in justice upon offenders, that they might be still in some degree of reformation in their military state. Armies are too great bodies to be found in all parts at once.
The army was (what by example and justice) kept in good order, both respectively to itself, and the country: nor was it their pay that pacified them; for had they not had more civility than money, things had not been so fairly managed.
They were many of them differing in opinion, yet not in action nor business; they all agreed to preserve the kingdom; they prospered more in their unity, than uniformity; and whatever their opinions were, yet they plundered none with them, they betrayed none with them, nor disobeyed the state with them, and they were more visibly pious and peaceable in their opinions, than many we call more orthodox.
They were generally constant and conscientious in duties, and by such soberness and strictness conquered much upon the vanity and looseness of the enemy; many of those fought by principle as well as pay, and that made the work go better on, where it was not made so much matter of merchandise as conscience: they were little mutinous or disputing commands; by which peace the war was better ended.
There was much amity and unity amongst the officers, while they were in action, and in the field, and no visible emulations and passions to break their ranks, which made the public fare better. That boat can go but slowly where the oars row several ways; the best expeditions is by things that go one way.
The army was fair in their marches to friends, and merciful in battle and success to enemies, by which they got love from enemies, though more from friends.
This army went on better by two more wheels of treasurers and a committee; the treasurers were men of public spirits to the state and the army, and were usually ready to present some pay upon every success, which was like wine after work, and cheered up the common spirits to more activity.
The committee, which the House of Commons formed, were men wise, provident, active and faithful in providing ammunition, arms, recruits of men, clothes: and that family must needs thrive that hath good stewards.