The South African
Military History Society

Die Suid-Afrikaanse Krygshistoriese Vereniging

Leonardo's Inventions for War

by Alan Mantle

Address to SAMHS Jhb branch on 11 February 2010

.... everyone best remembers Leonardo da Vinci as the painter of the Mona Lisa (1503-1506), the Last Supper (1495) and for many of his other great works of art

...... but he is best described as the archetype of the Renaissance man

He created, innovated and researched in mathematics, mechanics, geology, botany, hydraulics, architecture, sculpture, music, optics, astronomy, philosophy, all with success.

... made detailed drawings of human anatomy, still relatively unknown at that time

So his work in the military arts that we will discuss this evening is just another one of his astonishing multiplicity of talents:

.......... necessary to touch on the political background to Leonardo's life to understand this vocation .....

In the fifteenth century, Italy was divided into many small independent states.

Much of Europe - and almost all of Italy, with its belligerent city-states - was at war. Compared with armies from the Middle Ages, Renaissance-era armies were more orderly tactical entities, that in turn, required more effective weapons.
Military engineering was a major art.

Resume of his life

April 1452 Born near Vinci (Tuscany) - Illegitimate son of a notary Ser Piero di Antonio
1469 Apprenticed to famous art workshop of Verrocchio (Florence) & accepted into guild of artists in 1472
1472 - 1481 Florence: Early famous religious paintings but never really part of the Medici entourage
1481 Letter to Ludovico Sforza and move to Milan
1482 - 1498 Milan - military projects and also his great works as an artist, sculptor, architect & engineer
1499 French invade Milan and he flees to Venice
1499 - 1500 Naval War Designs for Venice Republic
1501 - 1502 Military Engineer to Caesare Borgia
1503 - 1515 Florence, Rome & Milan - artist and studies of flight, geometry and anatomy
1516 Moves to France invited by Francois I May 1519 His death at Cloux near Amboise

...... 1481 (aged 29) ... already a recognised artist but he was never really accepted into the Medici entourage [so] he decided to leave Florence. This prompted him to write to the Duke of Milan (Did everyone read the letter that was distributed before this talk ?)

Leonardo [was] in reality a closet pacifist - he actually worked as a military engineer in three periods of his life,

* when he was in Milan under the patronage of Ludovico Sforza the Duke of Milan
* then later, with the French invasion in 1500 he went into "exile" in the Maritime Republic of Venice and developed his naval studies under the Doge
* and lastly, in Urbino, in 1502 together with Macchiavelli as an envoy sent from Florence to the court of Cesare Borgia Duke of Urbino.


To follow the story of Leonardo's life and his works we have his own manuscripts and his enormously prolific output.
There are something over 7,000 pages of manuscript in Leonardo's hand in his characteristic "mirror-image" hand-writing, and also other writings have been lost.

These manuscripts are a map of Leonardo's mind.

Those that we are concerned with this evening come from 2 sources: Codex Atlanticus & the Codices of the Institut de France

Various subjects are covered: military art, optics, geometry, the flight of birds, hydraulics.

The Codex Atlanticus is kept in the Ambrosiana library in Milan, and consists of twelve leather-bound volumes.

In 1796, the year of Napoleon Bonaparte's arrival in Milan. he ordered the manuscripts to be transferred to Paris, and later some retumed ... So the result is that we have the largest concentration of notebooks there in France. Others are in Turin, London, Madrid and Seattle.

Designing Fortresses

With the advent of the use of gunpowder and the development of the artillery that were introduced in the second half of the 1400s, the medieval castles were no longer an inviable form of defence and their concepts and structure had to be completely revised.

Leonardo experimented with star shaped layouts.

What is notable here, is the introduction of the projecting battlements
These same concepts were applied a century later by the Grand Duke Ferdinand I when he built the Fortezza del Basso in Florence.
In his tower design we can see further innovations to the fortified Renaissance architecture.
Traditional battlements are sustained by a series of corbels ...

Also tower escarpment, meant to resist the shocks caused by firearms.
In 1502 .... for the modifications to that at Urbino ?

The innovations that were introduced related to the internal communications, the increased fortification of the entrances with Ravelins in the shape of triangular bastions and a series of self contained separate units within the fortress;
The two concentric walls stand in defence of the sturdy tower at the centre, which was probably where the lord of the manor lived.

Attack & Defence of Fortresses

Many of Leonardo's offensive weapons [were] designed to increase the firepower and their effectiveness .... Contrary to the 1 to 1 type of engagement that was typical of warfare in that period, he introduced a "multiplying" factor in defence and attack In 1479 Florentine garrisons came under siege and Leonardo worked, both on defences against the assault on the city but also on systems for attacking fortresses and scaling the walls.

[This was] Active not passive siege defence
One system using a system of levers could simultaneously push a number of rigid assault ladders away from the fortress wall
In another a large cog, when set in motion, simply swept the soldiers from the walls by unbalancing them.

For systems of attack, Leonardo proposed a mobile structure with an armoured bridge that could rest on the enemy walls, allowing the assaulting troops to pass over the moat


Though the newer artillery weapons were starting to take hold in his day, the older weapons were still in wide-spread use and Leonardo designed a large range of catapults, crossbows and slingshots, [making] existing designs ..... more efficient and /or easier to operate ..... his developments were towards multiplying the "fire power" of an individual or that of his armament.

Catapults to hurl stones

The model represents a wooden spring catapult, the laminar structures for enhancing spring flexibility and ensuring effectiveness to the hurling action.

Mechanized Crossbows

He envisaged that crossbows could be employed as effective artillery pieces;
use of mechanized techniques to increase their range and launch large arrows
He also designed this giant crossbow .... known as a "ballista".

Cannons & Machine guns

It was in 1340 that artillery was used for the first time in Europe (battle of Rio Salado .. Alfonso XI vs Marinid moors)
Stone balls were propelled by exploding gunpowder. These cannons weren't all that practical on the battlefield mostly because of their weight and lengthy loading time, [while] Leonardo's improvements were [practical]

Split-Trail Gun Carriage

This model is an example of a split-trail gun carriage, ... [it] features a traversing mechanism, which allows greater angles of elevation and can be rotated quickly both horizontally and vertically.
[He] studied elevating mechanisms
He wanted to increase the rate of firing weapons and so designed machines with multiple cannons, forerunner of the modem machine gun. Two of these used racks of eleven or fourteen guns.

[He].invented a multiple form of loading and firing.

While the top row was being fired the next rack was loaded at the same time as a third rack was cooling off.

Another design had the guns in a triangle spread for greater distribution of the projectiles.

33 Barelled Organ (machine gun)

One of his early innovations was to design breech-loading cannons as against muzzle-loading. By using several cannons in rotation one would be firing, while another would be loaded and the third cooled by water ..

Ogival Projectiles

With regard to projectiles,. Leonardo wrote that "A moved part will draw no benefit from not having greater power than the force resisting it." This theorem anticipated Newtons "Principia Matematica" by some 200 years.

These designs highlight remarkable intuition on the effect of air on projectiles fired by cannons ....[They are] shape[d] to ensure trajectory stability and firing efficiency: thus the projectiles have a modem shape and are provided with fins.

[There was a need for an] efficient system of igniting the gunpowder and so Leonardo invented the wheel-lock, a system which was much more reliable, than the flintlock. Centuries after Leonardo's death armies would adopt his system.

Offensive Mobile attacks


In his letter to Ludovico Sforza, Duke of Milan, Leonardo wrote that:
" I have plans for bridges, very light and strong and suitable for carrying veryeasily, with which to pursue and at times defeat the enemy; and others solid and indestructible by fire or assault, easy and convenient to carry and place in position". In the 20th C these were commonly known as " Bailey Bridges"

His documents contain designs for a number of bridges.
There is an arched bridge which gains its strength from the shape. There are military flying bridges used for crossing rivers and to counter the problem of river banks of different heights they included adjustable jacks.

Some bridges were mounted on pilings, while others were swing bridges. They were designed to be light, manoeuvrable and quickly assembled.

Mobile attacks - Scythed Chariots

There are several designs for horse-drawn scythed chariots among Leonardo's sketches.

The Armored Tank

Leonardo was to say, in his introductory letter to the Duke of Milan, that, "I shall make covered chariots, that are safe and cannot be assaulted; cars which fear no great numbers when breaking through the ranks of the enemy and its artillery. Behind them, the infantrymen shall follow, without fearing injury or other impediments"

His design of a tortoise-shaped tank, reinforced with metal plates, with an inner turret and armed with guns. The tank was to be operated from inside by 8 men, who would turn the cranks attached to trundle wheels to move the driving wheels.

. .it was to be a further four hundred years after he died before World War 1 saw tanks go into use during wartime ..

War at Sea

Fast ramming boat

The hull of the ramming boat is very strong, with no sails and fitted with a metal ram just under the water level. The most significant characteristic of the boat is its high speed and its consequent collision strength. High speeds are reached thanks to the shape of the hull, with a 12 to 1 ratio between length and width.

This other example is a destroyer for disabling an enemy vessel by bringing down its sails and then boarding it

In this design, the covering shield provided protection against the enemy ships and allowed the vessel to get close to the enemy without the cannon being noticed.

Another offensive means is this semi-submersible boat design (sometimes termed Leonardo's submarine)

The 'submarine' was simply a shell with room enough for one person to sit inside. It was topped with a conning tower which had a lid and he described it as a "ship to sink another ship." He had already devised a method by which divers could separate the planks of ships .... It predated the first offensive submarine by more than 250 years (?)

Although Leonardo's submarine never made it off paper, Leonardo was commemorated during WW II, when Italy named one of its hero subs the Leonardo da Vinci. (it sank 17 Allied ships)

Leonardo's double-hulled boats.

This would not only solve the problem of ramming, but also that of divers interfering with the vessel.

He designed air-filled bags which divers could attach to the hulls of a sunken ships in an attempt to re-float them ... and then designed bilge pumps that would extract the water and then dry the holds of ships. Note the design of the first conical valves

Leonardo's design for an underwater breathing apparatus

Other drawings for diving suits included a coat with a pouch to hold a wineskin to store air. His concept of storing air in a wineskin was revisited in 1825 when an aqualung for compressed air was outlined by the English engineer, William James. The necessary valve was designed by Emile Gagnon and Jacques Cousteau only in 1943 (over 400 years later)

In the last 100 years Flight has played such a pre-eminent part of warfare that Leonardo's work must have a place here. His fascination for flight [is shown in his manuscripts] (In the year1500, just about 400 years before the Wright brothers' success)

There are many manuscripts and notes relating to Leonardo's study of birds and their flight. He initially focused on mechanical flight intended to be operated and leave the ground thanks solely to elaborate mechanisms and human muscular effort.

Flapping Wing structure

This drawing shows that Leonardo was trying to fit the leaf-spring mechanisms in use for land machines to his flying devices. Leonardo's realization that human strength alone would hardly manage to make mankind fly.

Wing Structure

The wing structure study marked a critically important moment in Leonardo's endeavour to design a machine capable of making mankind fly.
With this study, Leonardo demonstrated in practice how wings can sustain weights. He found that if the long lever is pushed down fast enough, the connected wing will lift a bench as heavy as a man. Studying the ratio between the weight and the wingspan of a duck..

Glider with Man

Leonardo started to study gliding flight. The wings, an imitation of the wings of bats and of large birds, are fixed in their innermost section and mobile in their outer section. The latter in fact can be flexed by the flier by means of a control cable maneuvered through handles. (The comparison to the present day use of ailerons in flight is fascinating)

Leonardo's parachute

Leonardo's parachute consisted of a sealed linen cloth held open by a pyramid of wooden poles, about seven metres long.
The famous skydiver Adrian Nicholas tested Leonardo's design in South Africa in 2000, jumping from a hot-air balloon at 3000 metres.
A foldable silk parachute, with a hole near the top was developed and used in the late 18th century. The late 19th century saw the introduction of the harness and the concept of packing the parachute in a container. However, it was not until 1920 that the modern fold-up parachute with a ripcord was patented

Air screw

Leonardo wrote "(I believe that if this mechanism is spun rapidly) the screw will rise up high into the air."
In studying the air screw, Leonardo anticipates by centuries the formulation of the tractive power of the helix and thus the helicopter.

In conclusion I would like remind you that as a scientist, Leonardo had no formal education in mathematics or Latin and his scientific studies were largely ignored by other scholars. His approach to science was one of intense observation and detailed recording, his tools of investigation being almost exclusively his eyes. His joumals give insight into this investigative processes.

The full extent of his scientific studies has only become recognized in the last 150 years. Many of his designs - for flight, the tank, the submarine - were never realised or developed because they were too advanced for the capabilities of that time. Others, for example the movable dykes to protect Venice from the tidal invasions, proved too costly or impractical then but were finally realised only some 60 years ago. Some of his smaller inventions entered the world of manufacturing unheralded, but as you have seen this evening Leonardo was brilliantly able to advance science as well as conceiving ideas vastly ahead of his own time.

Text of the letter which was handed out before Alan started his lecture:

Extract from Leonardo's letter (1480) to Ludovico Sforza Duke of Milan

Most illustrious Lord, Having now sufficiently considered the specimens of all those who proclaim themselves skilled contrivers of instruments of war, and that the invention and operation of the said instruments are nothing different to those in connom use: I shall endeavour, without prejudice to any one else, to explain myself to your Excellency showing your Lodship my secrets, and then offering them to your best pleasure and approbation to work with effect at opportune moments as well as all those things which, in part, shall be briefly noted below.

1) I have a sort of extremely light and strong bridges, adapted to be most easily carried, and with then you may pursue, and at any time flee from the enemy; and others, secure and indestructible by fire and battle, easy and convenient to lift and place. Also methods of burning and destroying those of the enemy.

2) I know how, when a place is besieged, to take the water out of the trenches, and make endless variety of bridges, and covered ways and ladders, and other machines pertaining to such expeditions.

3) If, by reason of the height of the banks, or the strength of the place and its position, it is impossible, when besieging a place, to avail oneself of the plan of bombardment, I have methods for destroying every rock or other fortress, even if it were founded on a rock.

4) Again, I have kinds of mortars; most convenient amd easy to carry; and with these can fling small stones almost resembling a storm; and with the smoke of these causing great terror to the enemy, to his great detriment and confusion.

5) I have means by secret and tortuous mines and ways, made without noise to reach a designated {spot}, even if it were needed to pass under a trench or a river.

6) I will make covered chariots, safe and unattackable which, entering among the enemy with their artillery, there is no body of men so great but they would break them. And behind these, infantry could follow quite unhurt and without any hindrance.

7) In case of need I will make big guns, mortars and light ordnance of fine and useful forms, out of the common type.

8) Where the operation of bombardment should fail, I would contrive catapults, mangonels, trabocchi and other machines of marvellous efficacy and not in common use. And in short, according to the variety of cases, I can contrive various and endless means of offence and defence.

9) And when the fight should be at sea I have kinds of many machines most efficient for offence and defence; and vessels which will resist the attack of the largest guns and powder and fumes.

10) In time of peace I believe I can give perfect satisfaction and to the equal of any other in architecture and the composition of buildings public and private; and in guiding water from one place to another.

And if any one of the above-named things seem to any one to be impossible or not feasible, I am most ready to make the experiment in your park, or in whatever place may please your Excellency -- to whom I commend myself with the utmost humility.

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