Leonardo da Vinci’s war machines

September 25, 2026

Tanks, giant crossbows and multi-barrel cannons: Leonardo da Vinci’s war machines, combining technical ingenuity with the ethical dilemmas of the Renaissance.

Leonardo da Vinci was not only an artist, but also a designer of war machines, and he devised crossbows, cannons and other weapons. One of his most daring inventions was the armoured vehicle, conceived as an armoured machine with cannons arranged around its entire perimeter, powered by cranks connected to cogwheels and ideally operated by men. These designs were never put into practice because they often contained design flaws, probably deliberately introduced by Leonardo to prevent their use in warfare, but they demonstrate his visionary approach to technology applied to warfare and the ingenuity that led him to imagine solutions that were unthinkable for his time.

TABLE OF CONTENTS

• Was Leonardo the engineer at the service of war?
• Leonardo’s armoured vehicle
• The giant crossbow and siege weapons
• Multi-barrel cannons and rapid-fire weapons
• Other military designs: from the scythed chariot to naval weapons
• The ethical dilemma between love of life and war machines
• Leonardo’s legacy and modern reconstructions

Was Leonardo the engineer at the service of war?

During the Renaissance, the Italian city-states were in constant conflict, and local rulers were always looking for engineers capable of providing new solutions to strengthen their supremacy.

Leonardo skilfully found his place in this context and, in his famous letter to Ludovico il Moro dated 1482, presented himself not as a painter or musician, but as an expert in war machines: movable bridges, cannons, and defensive and offensive devices. Only at the end did he mention, almost in passing, that he could also paint.

This choice shows how aware Leonardo was of the value of technical skills and how military engineering provided privileged access to the favour of the courts. Despite his peaceful nature, he was ready to take advantage of this opportunity to finance his studies and obtain the support he needed to pursue research in a wide variety of fields.

Leonardo’s armoured vehicle

Among Leonardo’s most famous war machine designs is his armoured vehicle, which anticipated the idea of the modern tank by centuries. Leonardo’s armoured vehicle was conceived as a circular, armoured structure resembling a giant tortoise, equipped with cannons positioned around its perimeter to fire in all directions.

The idea was to design a vehicle that could be manoeuvred by soldiers using cranks to turn the wheels. However, the gear system contained a flaw that would have prevented the vehicle from moving, as the wheels were connected in such a way that they would block each other.

Some scholars argue that this was an unintentional error, while others believe Leonardo included it deliberately to prevent the machine from actually being built and used in warfare. In any case, the idea of a mobile armoured vehicle remains one of the most visionary concepts of his time.

The giant crossbow and siege weapons

In his codices, Leonardo also drew a giant crossbow approximately 25 metres long, mounted on a wheeled carriage. The crossbow was designed not only to strike the enemy with stones, bolts or explosive bombs, but above all to inspire fear through the visual impact of such an imposing weapon, as part of the psychological strategy of warfare.

Alongside the crossbow are designs for catapults, trebuchets and siege weapons, improved through ingenious mechanical solutions capable of making reloading faster and firing more accurate, anticipating the emphasis on efficiency that would later become central to modern artillery.

Multi-barrel cannons and rapid-fire weapons

Another extraordinary invention by Leonardo is the 33-barrel cannon, a kind of “Renaissance machine gun”, designed with three rows of eleven barrels each, mounted on a rotating support. The idea was that while one row was firing, another could be loaded and the third could cool down: in this way, continuous fire could be maintained without the downtime typical of traditional artillery.

The weapon was never built, but the design demonstrates just how far ahead Leonardo was in anticipating the military needs of his time. In an era when each shot took several minutes to reload, a weapon of this kind would have been revolutionary.

Other military designs: from the scythed chariot to naval weapons

Leonardo’s notebooks reveal many other war machines, including the scythed chariot, with rotating blades designed to spread panic among enemy infantry, machines for launching stones or incendiary bombs, mobile ladders for sieges and portable bridges that could be quickly assembled and dismantled.

Leonardo was also interested in naval warfare, imagining ships armed with multiple cannons and devices designed to damage enemy vessels. Some of his solutions, such as flotation systems for the rapid transport of troops, demonstrate his ability to adapt mechanical principles to different contexts.

The ethical dilemma between love of life and war machines

Leonardo’s notebooks include many designs for war machines, yet da Vinci had a profound love of nature and a genuine respect for life. For this reason, some historians believe that his military designs were more of an intellectual exercise than an expression of a genuine desire for destruction, and that this may explain why many of the machines he designed contain technical flaws that would have made them unusable.

This ambivalence reflects the tensions of the Renaissance, with Italian states on the one hand racing to equip themselves with increasingly powerful weapons and, on the other, the sensitivity of a man who regarded war as humanity’s “most bestial madness”. Leonardo’s war machines, therefore, lie somewhere between visionary imagination and moral conscience, between technical innovation and ethical reflection.

Leonardo’s legacy and modern reconstructions

Models of Leonardo’s armoured vehicle, giant crossbow and 33-barrel cannon are displayed in various museums around the world, allowing visitors to appreciate both the ingenuity and the limitations of his inventions, and several of these designs have been reconstructed by scholars, museums and craftsmen, demonstrating the soundness of Leonardo’s ideas.

Thanks to computer simulations, it has also been possible to test the effectiveness of some of his designs, which would have been fully functional if built using modern materials. This confirms that, more than an inventor of weapons, Leonardo was a forerunner of mechanical and engineering principles that would only find practical applications centuries later.

This article was originally published in Italian on 21 July 2025

You can read the Italian version of this article here >