Crossbow
Today, a hard-to-abandon military technology. The University of Houston presents this series about the machines that make our civilization run, and the people whose ingenuity created them.
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History is full of instances where armies cling to outmoded weapons. Take WW-I cavalry charges: Here was a weapon that was thrilling to watch. But it had, long since, proved useless against modern fire power. Think “Charge of the Light Brigade.” Now I’ve been looking into the crossbow – that souped-up, mechanized bow-and-arrow.
Medieval crossbow
We’re aware of the crossbow’s tenth-century European adoption, since the monasteries had begun keeping historical records. But it was far older. It was an ominous weapon that’d risen, then fallen, many times before, over the millennia.
Its strings are drawn mechanically, then triggered. They launch a missile with much greater mid-range penetrating power than an arrow – especially against metallic targets. Scary, No? But they were also temperamental – slow to arm, hard to handle in a muddy field. They could get only one bolt off in the time a longbowman had fired four arrows. And they had less range.
Model showing a Medieval Crossbowman’s equipment
The Chinese used crossbows thousands of years ago. And they often used a mix of archers and crossbowmen to get the best of both worlds. But their armies became more focused on cavalry, and crossbows were useless on horseback. Chinese needs and its views on how to wage war, ended crossbow use until around the tenth century – about the same time they reappeared in the West.
They also appeared, but failed to gain traction in ancient Greece. The Greeks saw military combat as a collective action by formations. It was not the work of sharpshooters. Roman thinking was somewhat similar. They focused on drill and discipline. The crossbow looked like a political threat – one that undermined the virtues they wanted to instill in their fighting forces.
So why did they reappear in Tenth Century Europe? Well, the wealthy lords of the waring states could afford them. And they could draft untrained soldiers and quickly train them to use them. Sure, crossbows could be temperamental. But they didn’t need the skill of a good archer. And a crossbow bolt could now penetrate the armor of a mounted knight.
Europe’s wealthy warrior class raised an alarm. Lowly commoners killing knights offended the whole royal structure. So, the Church stepped in. Pope Innocent II banned crossbows in 1139. Well, at least against other Christians. The ban, of course could not hold up. Within the century, crossbows were back in business. But only for a while. Guns were about to change everything. So their medieval resurgence was fairly brief.
So that’s how the long experiment of the crossbow rose and fell over millennia. Some inventions seem so right that we simply overlook their obvious weaknesses. Like the cavalry charge, this was a technology whose glitz repeatedly blinded people to limitations that might otherwise have been obvious.
I’m John Lienhard, at the University of Houston, where we’re interested in the way inventive minds work.
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Some online source material – all accessed in January, 2026.
General background on the crossbow:
Crossbow, Wikipedia.
https://en.wikipedia.org/wiki/Crossbow
(A general overview of crossbow history, mechanics, and use.)
Crossbows in ancient China:
Crossbows in Ancient Chinese Warfare, World History Encyclopedia.
https://www.worldhistory.org/crossbow/
(On early Chinese adoption, mass production, and tactical use of crossbows.)
Ancient Greek crossbow-type weapons:
Gastraphetes, Wikipedia.
https://en.wikipedia.org/wiki/Gastraphetes
(On the ancient Greek “belly-bow,” an early crossbow-like weapon.)
Context for longbow vs. crossbow use:
English Longbow, Wikipedia.
https://en.wikipedia.org/wiki/English_longbow
(Provides comparative context for rate of fire, range, and battlefield role.)
Earlier Engines episode:
The Crossbow, The Engines of Our Ingenuity.
The Crossbow | The Engines of Our Ingenuity
(An earlier episode dealing with medieval European crossbow use.)
This Episode first aired on February 2, 2026.