Oliver Cromwell: the secret of his military genius

In just two years, Oliver Cromwell made the journey from little-known MP with no experience of armed combat to brilliant, battle-winning leader. Martyn Bennett, author of Cromwell at War: The Lord General and His Military Revolution, reveals how a military novice became one of British history’s greatest warriors.

This article was first published in the February 2017 issue of BBC History Magazine

Thomas Wyck’s painting of Oliver Cromwell on horseback. (Bridgeman)
Thomas Wyck’s painting of Oliver Cromwell on horseback. (Bridgeman)
 

In the early evening of 2 July 1644, two powerful armies faced each other across an expanse of wild meadow eight miles west of York. On one side was gathered a royalist force led by King’s Charles I’s German nephew, Prince Rupert, and the Marquis of Newcastle. On the other, occupying 
a ridge known as Bramham Hill, stood 
an allied army of parliamentarians and Scottish covenanters. 

At about 7pm, with a storm approaching and light slowly beginning to fade, the royalists decided that there was no prospect of a battle that day, and started to stack arms, find food and unsaddle horses. Yet, just as they began to settle down for the night, their enemies struck. 

On the western fringe of the battlefield, Lieutenant General Oliver Cromwell led three lines of horse regiments down from the hill towards the royalists camped on the low ground in front of them. The front line advanced at a trot, then a canter, a gallop and a charge. Each man was pressed up against his colleagues with his sword drawn, ready to smash into the enemy. Caught unprepared on rough ground, those royalists who had managed to mount their horses in an attempt to launch a counterattack were driven back.

As Cromwell introduced more men into the fight, the royalist right flank broke and began to flee. But not all the royalists had such a bad experience. On the opposite flank, they caused such chaos that the three parliamentarian commanders – Lord Fairfax and the earls of Manchester and Leven – fled, thinking the day was lost. However, so devastating was Cromwell’s attack that these royalist advances were to no avail. Parliament had won a famous victory. “We never charged but we routed the enemy,” he later wrote. “God made them as stubble to our swords.”

Oliver Cromwell was well on his way to becoming the most powerful man in Britain and Ireland.

 

Remarkable journey

Oliver Cromwell’s battle-winning intervention at Marston Moor was remarkable enough in itself. But what made it even more extraordinary was the fact that, just two years earlier, at the outbreak of the Civil War between the forces of parliament and Charles I’s royalists, he was a little-known MP who had never taken up arms, let alone led men into battle. His journey from obscure country gentleman to great warrior is among the most remarkable in British military history.

That journey began when Cromwell became MP for the Cambridgeshire market town of Huntingdon in 1628. The 29-year-old entered parliament at a fraught, feverish moment in its history, when Charles I’s relationship with his MPs was becoming increasingly strained. There’s a great deal we don’t know about Cromwell at this time, but it seems that he was alarmed by the Catholic drift of the king’s religious policy, and repelled by the notion of Charles’s personal rule (as the king chose to govern without recourse to parliament). It’s little surprise, then, that when war broke out between king and parliament in the summer of 1642, he 
was quick to join the parliamentarian cause under firstly Lord Grey of Wark and then the Earl of Manchester. 

Cromwell’s brilliant performance at the battle of Marston Moor – depicted here – won England’s north for parliament and turned him into a truly national figure. (Bridgeman)

 

Cromwell began the war as a captain of horse, but it wasn’t long before his sharpness of mind – one that could quickly take in the nature of a landscape and the military opportunities that it provided – had won his superiors’ admiration (particularly during the Edgehill campaign of autumn 1642). In January 1643, with both sides seeking to promote proven soldiers to create regional officers, he was made a colonel. 

As a captain of horse, Cromwell had raised 80 men and chosen officers from his extended family or social and religious connections. His men were harquebusiers, the only heavy cavalry on the Civil War battlefield. Clad in a buff coat, a back and breastplate and a triple-barred lobster-tail helmet, they were armed with a heavy, straight-bladed sword and a short musket or carbine and two pistols.

Now, as a colonel, Cromwell could turn his single troop of harquebusiers into a regiment by recruiting five more troops from scratch or amalgamating them from elsewhere. 

 

Self-help guides

Contemporary military manuals suggest that it took years to acquire the experience and the skill to be a captain of horse – let alone a colonel. However, Cromwell had managed it in a matter of months. But how? Part of the answer may lie in the very manuals that insisted that his meteoric rise wasn’t possible.

The late 16th and early 17th centuries was a boom time for such ‘self-help’ military guides, offering both personal and professional tracts on battlefield acumen. Military greenhorns like Cromwell could learn rapidly from texts such as John Cruso’s Militarie Instructions for the Cavallrie (1632), William Barriff’s Military Discipline or the Young Artillery Man (1635) and the Swedish Intelligencer, which gave accounts of large battles on the continent.

If Cromwell did indeed read these manuals, then it was soon paying dividends, for at a skirmish near Grantham in Lincolnshire in May 1643 – part of an ultimately vain attempt to capture or weaken the key royalist garrison at Newark, north-east of Nottingham – he used his learning to brilliant effect. 

Oliver Cromwell portrayed in an oil on panel painting. (Bridgeman)
 

At one point in the engagement, Cromwell found himself being chased towards Grantham by a force of royalist horse and dragoons. But then, having held an on-field council with Captain John Hotham, he decided to turn on his pursuers, using the so-called Swedish method. The parliamentarian horse advanced on their enemies, steadily increasing their speed to a charge. 
All the while, Cromwell’s front line was linked together, with each rider’s right knee lodged behind the left knee of the rider to his right. This formed a solid wall of horseflesh and armoured trooper at the point of impact. 

The royalists did not charge to meet Cromwell’s troops – instead “standing firm to receive us”, as Cromwell later wrote – possibly confident that their carbine and pistol fire would deflect the attackers and force them to swerve to the flanks. Their confidence was misplaced. “Our men charging fiercely upon them, by God’s providence they were immediately routed, and ran all away,” he later recalled. “His men then chased the broken enemy, inflicting most casualties during the royalists’ flight. 

 

Under siege


Cromwell met with similar success two months later while advancing towards Gainsborough, in an attempt to break a royalist siege of the Lincolnshire town. As the parliamentarian troops advanced along what is now the A156, they were met by several royalist horse regiments and dragoons or musketeers, led by Sir Charles Cavendish.

Cavendish’s men were stationed on a plateau on top of what is now known as Foxby Hill, presenting Cromwell and General Sir John Meldrum with the prospect of launching an attack across steep and broken ground. 

It was a risky move. Had Cromwell’s men been forced back down the hill, they would have run into marshy ground near the river Trent. Undeterred, they went on the offensive anyway – with spectacular success.

The royalists were unable to prevent Cromwell’s men from cresting the hill. 
(We know from the fatal injury suffered by royalist John Hussey that the shooting was at close quarters.) Now, with both sides having formed a battle order on the plateau, they started to charge each other. 

Royalist commander Charles Cavendish died in a clash with Cromwell’s troops. (Bridgeman)
 

Cromwell’s account noted that the fight was protracted before the royalists began falling back and breaking up. There then followed a fast pursuit, but Cromwell kept tight control of part of his regiment: “[I] kept back my major, Whaley, from the chase, and with my own troop and another of my regiment, in all being three troops, we got into a body.” 

It was just as well he did, for Cavendish, employing his own reserve, attacked the parliamentarian reserve and was meeting with some success – until Cromwell rammed into them from behind. The royalists were propelled into a headlong plunge down Foxby Hill across the nearby Lea Road into the marshes beyond, where they became literally bogged down. Cavendish himself was killed as he foundered in the wetlands. 

These were only minor battles and in no way did they change the course of the Civil War. The parliamentarian retreat from Newark continued after the fight at Grantham, and Gainsborough fell to the royalists within hours of the clash on Foxby Hill. Yet in both engagements, Cromwell demonstrated considerable foresight and ability. He understood the need to charge the enemy head-on and to keep up the pressure after the initial clash. He also showed that, while a bloody close-quarter pursuit is of great value in wrecking an enemy force, keeping a reserve and simultaneously retaining tight control of front-line troops were equally important. 

As well as being a brilliant tactician, Cromwell had a keen eye for strategy. Probably more than any other commander in the region, he recognised that possession of the royalist garrison at Newark was the key to regional control, and determined that those who worked with him were dedicated to the goal of capturing or at the very least neutralising it. He pressured superior commanders into taking a more aggressive line and, when they failed, he criticised them publicly. In doing so, he contributed to the reputational destruction of the Lincolnshire commander Lord Willoughby of Parham and eventually the Earl of Manchester himself, after he failed to tackle Newark in autumn 1644.

It was harsh but Cromwell was right. Newark would act as a major bugbear 
right until the end of the war. While the royalist garrison there was active, no parliamentarian commander could turn 
his back on the area.

 

Fierce loyalty

Cromwell’s tactical acumen, strategic foresight and gifts as a leader of men (he demonstrated great care for his soldiers – troubling over their training, their pay and their wellbeing – and fought with administrators and paymasters on their behalf) made him a truly formidable opponent. By the time he was appointed lieutenant general of horse under the Earl of Manchester in 1644, all he needed was experience of a major battle. Marston Moor would provide him with exactly that.

Early that summer, Manchester’s Eastern Association army joined Lord Fairfax and the Earl of Leven in besieging the Marquis of Newcastle in York. When Prince Rupert dramatically rescued the marquis on 1 July, the three besieging armies withdrew south-westwards before turning to face the pursuing royalists. When Cromwell and the Eastern Association horse arrived on the ridge of Bramham Hill, he saw that at the Tockwith end of what would be the battleground of Marston Moor, the royalists had begun to take possession of ground from which they could gain the upper hand over any force that positioned itself on the ridge. 

Despite facing artillery and horse regiments, Cromwell attacked and forced the royalists back onto the lower ground of the moor. At one stroke, he had ensured not only that the ridge’s western end was secure but that the royalists were at a disadvantage, confined as they now were to the lower ground. He also effectively defined the western end of the battlefield as abutting two tracks, one running north from the Tockwith to Long Marston road and one running south from it to Bilton. From here, Cromwell and the Scottish cavalry officer David Leslie led the allied army’s charge on the royalists’ right flank, an attack so devastating that it offset any success the royalists had on the battlefield. Cromwell’s intervention cost Rupert and Newcastle the battle. More crucially still, it forced King Charles to effectively abandon the north of England. 

Cromwell’s brilliance at Grantham and Gainsborough had forged him a formidable reputation – but on a regional level. Marston Moor changed all that. Now he was a national player – one who the 17th-century soldier and author Lionel Watson hailed as “the great agent in this victory”.

Marston Moor had seen Cromwell build on the lessons of Grantham and Gainsborough. His success was based around careful use of the available landscape, tightly knit charges, a reserve force capable of delivering a second blow, and a front line able to remain in tight order even after hard-won victories.  

Oliver Cromwell would go on to even greater heights over the following years – most notably in the spectacular Worcester campaign of 1651. But it was the military insights honed on the battlefields of the east Midlands that set him on a trajectory to becoming Britain’s most brilliant general.   

 

The countdown to Marston Moor

The first 15 years of King Charles I’s reign were marked by growing disaffection across his kingdom at his religious policies – some Protestants feared that he intended to restore the Catholic faith to England – and his apparent determination to rule without recourse to parliament.

By the early 1640s, the gulf between the king’s royalist supporters and his parliamentarian opponents had become a chasm, and conflict appeared inevitable.

When war broke out, in August 1642, a broadly royalist north and west of England was ranged against a chiefly parliamentarian south and east.

Neither side gained a decisive advantage in the early months of the war, with the first pitched battle – at Edgehill in Warwickshire – proving inconclusive. But in 1643, directing the royalist war effort from his base in Oxford, the king appeared to gain the upper hand, seizing Yorkshire and Bristol. Then, in the autumn of 1643, the tide turned again – the royalists were forced to raise the siege of Gloucester and the Scots threw their weight behind the parliamentarian cause.

By the time two large armies lined up against one another at Marston Moor just outside York, on 2 July 1644, the scene was set for Oliver Cromwell to make an intervention that would all-but secure parliament the north of England.

Martyn Bennett is professor of early modern history at Nottingham Trent University and author of Cromwell at War: The Lord General and His Military Revolution.

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