5 Key Battles That Defined Oliver Cromwell

Oliver Cromwell was a giant in British politics and a skilled general who learned his trade during the violent English Civil Wars.

Aug 14, 2023By Matthew Doherty, Msc East Asian Relations, BA Asia Pacific Studies

oliver cromwell battles


The mid-17th century was the most politically volatile time in England’s history. Oliver Cromwell was the key figure of that period, ruling England as Lord Protector for the first and only time the nation has been a republic. As a general, Cromwell pioneered new military tactics and won a string of victories that made England a world power. He was such a towering force that, with his death, the fledgling republic collapsed. In Ireland, his name still evokes hatred and division. These are the five battles that made the man.


1. Winceby: October 11th, 1643

oliver cromwell ironsides
Cromwell’s Troopers by George Wright, 19th century, via Wikimedia Commons


At the start of the First English Civil War, Cromwell was a relatively prosperous country squire in his early forties. When war against the King became inevitable, Cromwell set about recruiting for the Parliamentary forces.


The small Battle of Winceby in 1643 showed Cromwell’s talents as a cavalry commander and marked him as a rising star in the army of the Parliament.


By the time of the battle, Cromwell had raised a crack unit of cavalry called the Ironsides. These horsemen were determined, loyal, and, most important for Cromwell, “godly.” But at Winceby, he was subordinate to the wealthy Earl of Manchester.

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Royalist forces were besieging the port city of Hull. To relieve the siege, Manchester marched his army into Lincolnshire. Near the village of Winceby, Cromwell’s cavalry became separated from Manchester and the main body of troops and ran headlong into a Royalist force.


The fight developed quickly, with about 3,000 men engaged on either side. Cromwell feigned a retreat with his Ironsides, only to reform and crash into the Royalists’ right flank. During the melee, Cromwell’s horse was shot from under him, but he remounted and continued to engage. Before long, the Royalist force broke. In the retreat, some Royalists were massacred when they became trapped against a wall in what is known today as Slash Hollow. Around 300 were killed.


While Winceby was not as decisive as other battles Cromwell fought, it showed his talent for command. The Parliamentary victory had been almost entirely down to his leadership and the discipline of the Ironsides.


2. Marston Moor: July 2nd, 1644


1644 saw a large Scottish army (known as the Army of the Solemn League and Covenant) enter England to engage in the war on the Parliamentary side. The commitment offered Parliament a decisive opportunity to tip the balance and defeat King Charles.


oliver cromwell marston moor
Marston Moor by John Gilbert, 19th century, image via World4


After taking Newcastle in the early part of the year, the summer months saw the Scottish army under the elderly Earl of Leven move south to besiege York, where they were joined by Parliamentary forces under Sir Thomas Fairfax and the Earl of Manchester. Cromwell was still a subordinate in Manchester’s force and commanded a good portion of the combined Scottish/Parliamentary cavalry.


Prince Rupert, the best Royalist field commander of the war, was determined to relieve the siege and smash the Scots. He made an incredible lightning march from Oxford and in a brilliant series of maneuvers, tricked the Covenanter/Parliamentary army into abandoning the siege. But he was still determined to risk everything by fighting a pitched battle.


Marston Moor was fought near York on July 2, 1644. Cromwell commanded the left wing of the Parliamentary cavalry. He would be pitted directly against Rupert and his experienced cavaliers.


The battle hung in the balance for hours. At one point, the Parliamentary right gave way. Royalist horsemen crashed into the center, and a good portion of the Scottish/Parliamentary infantry began to buckle. At this point, the Earl of Leven left the field, believing the battle to be lost.


In an epic ride around the whole length of the battlefield, Sir Thomas Fairfax linked up with Cromwell’s hard-pressed men and helped him renew the assault on Rupert. During the fierce fighting, Cromwell had to leave the melee to get medical attention for a neck wound, but he quickly returned to lead his Ironsides to victory. Rupert’s horse finally gave way as the reformed Parliamentary infantry slammed into their Royalist counterparts.


Marston Moor secured Northern England for Parliament and was key in bringing about the King’s eventual military defeat. It also further marked Cromwell as a rising star.


3. Preston: August 17th-19th, 1648

oliver cromwell battle preston
The Battle of Preston and Walton by Charles Cattermole, 1877, via KeepYourPowderDry


Preston was the first major battle in Cromwell’s career in which he was in sole command of a Parliamentary army. The defeat and capture of King Charles in the First English Civil War precipitated a complex series of political maneuvers that saw Parliament try to wrangle a peace settlement with him.


But the King was negotiating in bad faith, all the while trying to convince the Scots to switch sides and invade England on his behalf. In July 1648, the Scots marched south. Known as the Engagers, they were supported by pro-Royalist risings in England and Wales.


Carlisle fell to the Engagers, and they proceeded into Lancashire. Cromwell made a rapid march to meet them, catching up with them near Preston in August. His New Model Army (NMA) would be outnumbered (8,500 Parliamentarians to 11,000 Royalists), yet he still decided to attack. A three-day running battle was fought in pouring rain among the narrow fields and thick hedgerows of the countryside around Preston. Much of the fighting was done at the regimental or company level, with limited direction from senior generals. In this sharp contest, the NMA colonels and captains proved they were far superior to their Royalist counterparts. Cromwell had promoted many of these men based on merit, whereas Engager officers were still generally men of higher birth who obtained their commissions because of their blood, not their capabilities. The fact Cromwell was able to delegate much of the battle to his officers and still come out victorious highlights the bonds of personal trust he had built up with them.


oliver cromwell portrait
Oliver Cromwell by Samuel Cooper, 1656, via Wikimedia Commons


Cromwell claimed 2,000 Engagers were killed, with a further 9,000 captured. Such a figure will certainly have been exaggerated, for this represents the whole of the Royalist force. What is clear is that Engager losses were significant enough to wreck the invasion plan, and NMA losses were tiny in comparison. Some captured Royalists were even transported to work as plantation slaves in the British West Indies.


In fighting this savage engagement, Cromwell had shown himself to be among the most capable Parliamentary field commanders. The NMA (largely his personal creation) was also proving unbeatable in open battle.


And Preston had further ramifications for Cromwell the man, convincing him that Charles could no longer be trusted. From this point, he was determined that only the death of the King would secure peace in the land, ominously saying, “I tell you, we will cut off his head with the crown upon it.”


4. Dunbar: September 3rd, 1650

oliver cromwell battle dunbar
Cromwell at Dunbar by Andrew Carrick Gow, 1886, via Historic-UK


The King did indeed lose his head on a bitterly cold January morning in 1649. From that moment, England was a Republic. But the new “godly utopia” was beset by problems. Not the least of which was a significant pro-Royalist Engager force still left in Scotland, this time declaring their allegiance to Charles’ son and heir, the future Charles II.


Dunbar is the most unlikely of all Cromwell’s victories. From a seemingly hopeless trap, the NMA not only survived but completely smashed a numerically superior Scottish force. Indeed, the Christian fundamentalist Cromwell was quick to attribute the startling success to the favor of the almighty.


At the beginning of September 1650, 11,000 men of the New Model Army were condemned to destruction. Cromwell had invaded Royalist Scotland earlier in the year, going up against the veteran Scottish commander David Leslie. Leslie had fought alongside Cromwell at Marston Moor just six years previously, but times had changed, and he now marshaled a force of 23,000 Scots in Edinburgh to oppose Cromwell’s invasion. Then he destroyed all the farms and drove off all the livestock between the English border and the city.


nma circa 1650
The New Model Army, 1645 by Angus McBride, 1989, via World History.biz


Cromwell marched in regardless but came up against strong defensive works near Edinburgh. The scorched earth policy then caused the supply situation to become critical. Camp diseases like dysentery began to ravage the English ranks as hunger gnawed at their bellies.


When Leslie realized that he outnumbered the NMA by over 2:1, he moved out of his works and managed to pin the sickly English force at Dunbar with only the sea to their backs. Worse for Cromwell, the Scottish army was deployed across Doon Hill, an imposing terrain feature. The only way out was directly through them.


Leslie and his men assumed the English were a beaten force and that their inevitable surrender would come quickly. They were wrong.


Pouring rain on the night of September 2nd allowed Cromwell to move a large portion of his army close to the Scottish right flank. At dawn the next day, Cromwell launched his men forward, shouting the Old Testament quotation, “Now let God arise, and his enemies shall be scattered!”


It was a desperate attack, but after fierce fighting, the English succeeded in smashing the Scottish flank. Then the NMA cavalry swooped in and rolled up the numerically superior Scottish army.


English casualties were in the hundreds. The Scots lost thousands, with many taken prisoner. Dunbar ranks as Cromwell’s most surprising and decisive long-odds victory.


5. Worcester: September 3rd, 1651

oliver cromwell battle worcester
After the Battle of Worcester by Francis Henry Newbery, 1924, via Art UK


For once, Cromwell would have the advantage of numbers at Worcester. In September 1651, the NMA bore down on yet another Scottish Royalist force that had invaded England. The future monarch Charles II was with this army. Hope that significant numbers of English Royalists would flock to the royal banner was dashed. The English population at that time was far too war-weary.


Occupying the town of Worcester, the Royalists were converged on by four Parliamentary armies, including Cromwell’s New Model. 15,000 Engagers would fight approximately double that number of Parliamentary troops. Despite some fierce resistance from the Scots outside the town, the NMA was relentless in their assaults, and the Royalists crumbled. Thousands of Engagers were taken prisoner for the loss of a few hundred Parliamentarians.


Worcester ended the so-called Third English Civil War. Parliament was secure, and Cromwell’s personal political capital became unassailable. He ruled the country as Lord Protector until his death in 1658. In that short time, he began to make England a global power.


Charles II fled the battlefield of Worcester in disguise, at one point hiding from Parliamentary troopers by climbing an oak tree. He eventually made it out of England and lived in exile. This finally changed in 1660 when, two years after Cromwell’s death, he was invited to rule England by the Parliament that had so bitterly opposed him. Nobody except a legitimate king could fill the political void left by Oliver Cromwell.

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By Matthew DohertyMsc East Asian Relations, BA Asia Pacific StudiesMatthew is a writer, editor, and teacher, specializing in all things military history related. His work has been published in the UK Defence Journal and the Small Wars Journal. He holds an Msc from the University of Edinburgh and a BA from the University of Leeds. In his spare time, he also writes science fiction stories.