Warhorses were one of the most deadly weapons on a medieval battlefield. But why didn’t they run away?

The medieval warhorse is, seemingly, a contradiction in terms.

Horses are prey animals. Their instinct, when confronted with loud noises, sudden movement or danger, is to run as far away as possible, as quickly as possible.

And yet, for centuries across the Middle Ages, these animals were incredible weapons of war. With armoured warriors in the saddle, they charged directly into some of the most terrifying scenes imaginable: walls of sharpened spears held by lines of screaming men.

And warhorses weren’t a peripheral tool, either. They were at the centre of medieval warfare. Mounted combat dominated European battlefields for hundreds of years, shaping the grand military strategies that upheld political power. Cavalry charges could decide entire battles, and the men who could afford to fight on horseback were part of a powerful military elite.

None of that was possible without horses that could be controlled under extreme stress. So how did they do it?

As historian Robert Liddiard explains on the HistoryExtra podcast, these horses were honed through immense financial investment and extraordinary, long-term training.

Why medieval warhorses mattered

But first, what was so special about warhorses anyway?

The answer, according to Liddiard, can be found in 1066’s battle of Hastings, which was a potent demonstration of the differences between a force that deployed warhorses – the Normans – in contrast to a force that didn’t – the Anglo-Saxons. “Arguably it's horses that allowed Duke William of Normandy to gain the edge,” he says.

“The warhorses provide mobility on the battlefield in a way that Harold Godwinson’s forces simply haven't got, and this has great tactical benefits. The possession of trained cavalry allows William to have greater tactical options and flexibility.”

A trained warhorse was, therefore, a force multiplier. And alongside the tactical advantage, they offered a psychological one, too. The sight and sound of armoured men charging toward you at speed could cause discipline to collapse before contact was even made.

That importance explains why medieval rulers increasingly treated horse production as a vital matter of attention, worth immense expense.

• Read more | Medieval warhorses: 5 moments horsepower changed the course of history

Breeding a medieval weapon of war

“What I can’t overstate,” Liddiard says, “is the amount of time, money, and effort that went into producing these warhorses. It is absolutely extraordinary.”

This wasn’t a matter of purchasing animals at market when war broke out. In England, the Crown maintained “a network of about a dozen horse studs across the kingdom, which are almost entirely devoted to producing warhorses.”

These royal studs controlled breeding from the outset. Foals were selected for size, strength and temperament, traits that were all essential for animals expected to remain responsive amid the chaos of battle. Calmness under pressure absolutely mattered as much as physical power.

From around the age of one, these young horses were weaned and moved into the next stage of development.

Growing up to fight

“We know quite a lot about the life course of these animals,” Liddiard explains.

In southern England, young horses were transferred to what were known as colt parks. Here, “you’ve got the equivalent of teenage warhorses roaming around by themselves.” This was a period of prolonged assessment of behaviour: how the horse responded to other animals and unfamiliar environments was all carefully monitored.

At around three years old, training intensified. Horses were placed “within a group of trained warhorses that itinerate around the kingdom where they learn their future trade.” This mattered because horses learn socially. By moving alongside experienced animals, younger horses absorbed calm behaviour through repetition and years of conditioning.

This was how the instinct to flee was supressed. But it wasn’t erased.

Only after years of preparation and training would a horse be deemed suitable for service and transferred into a noble or royal household.

From birth to battlefield readiness, “you could be talking about five to seven years,” Liddiard notes.

Time, money and risk

The length of time this took imposed an immense financial burden.

“You’re talking hundreds and thousands of pounds, cumulatively,” he says, adding that royal horse keepers often finished their annual accounts in deficit.

Medieval kings were acutely aware of the cost but accepted it because the military payoff was decisive. That’s something that still hasn’t changed.

“You talk to anyone who breeds and trains horses now and they always tell you how expensive it is. I can assure you it is absolutely the same in the Middle Ages.”

At times, the expense became unsustainable. In 1360, following the Treaty of Brétigny during the Hundred Years’ War, Edward III shut down England’s royal stud network. The decision reflected both a lull in the large-scale conflict, and the crushing cost of maintaining the system.

When warhorses failed

But even the best-trained warhorses could sometimes become a liability. And, when control over a warhorse failed, the consequences could be incredibly stark.

At Bannockburn in 1314, Scottish forces exploited terrain and dense spear formations to deny cavalry room to manoeuvre, turning horses into liabilities. At Bosworth in 1485, Richard III’s fall from his horse marked the collapse of his kingship.

But despite those rare instances, a medieval warhorse was an incredible boon to any army that could afford them. From William the Conqueror’s cavalry at Hastings to the mounted knights of the Hundred Years’ War, warhorses proved decisive in medieval warfare over centuries.

And they were the result of sustained human effort: generations of breeding, years of training, and vast financial investment, all geared toward teaching prey animals how to advance into battle, rather than flee.

Robert Liddiard was speaking to Spencer Mizen on the HistoryExtra podcast. Listen to the full conversation.