Dangerous Liaisons Leonardo

The year 1515 was a dangerous one for Leonardo da Vinci.

Caught up in Vatican intrigue,

he was betrayed by spies within his own camp

who denounced him as a sorcerer.

'He's not only dissecting the bodies of the dead, but even that of a woman with child.

-'There is no limit to the investigations of the Florentine.'

-Fetch Leonardo da Vinci.

Not for the first time, Leonardo the rebel and rule breaker,

was out of step with the times in which he lived.

This is the story of Leonardo da Vinci,

the man who set out to learn everything

and to read the mind of God.

The painter's mind should be like a mirror, reflecting everything in the natural world around him.

He must even be a second nature,

a universal master.

I will do things no-one in the past has dared to do.

I will think new thoughts, bring new things into being.

Even 500 years ago, Leonardo was seen as a miraculous figure.

His first biographer, Vasari, writes,

"Occasionally, heaven sends us someone who is not only human, but divine,

"so that through his mind and the excellence of his intellect, we may reach to heaven."

People have asked me over and over, is this the greatest genius ever?

I say, yes, that he is.

"What about Newton, Einstein?"

It's easy to point out that Newton's genius lay in one particular area,

that Einstein's genius was in a particular area.

But there's nobody like Leonardo.

Think of every area to which he turned his attention

and how every one was so beautifully created,

constructed and conceived of.

That has to be the furthest reach, I believe,

that man's mind has ever attained.

In 1498, Leonardo had completed his monumental painting of the Last Supper.

But his brilliant career at the Milan court was cut short as the French invaded.

His patron, the Duke of Milan, was imprisoned

and Leonardo's most ambitious work, the great clay horse statue,

was destroyed by the French troops.

Forced to flee,

Leonardo now travelled through the war-torn countryside in search of work.

This is how the wheel of fortune turns. Those briefly at the top are flung again to the bottom.

The Duke has lost his estates, his fortunes, his freedom.

But you know what they say - he turns not back who is bound to a star.

Leonardo needed a safe haven

and so he travelled eastwards from Milan to the Adriatic coast.

Throughout his life, Leonardo had been searching for a patron

who would allow him to develop his extraordinary, even visionary ideas. But he needed money.

And where better to find money than here - in 1500, one of the richest cities on earth, Venice.

Its vast wealth was based on commerce.

It was in a prime position on the trade route importing opulent goods from the Orient.

So it was a confident city, not easily intimidated.

But it was also a city in crisis.

The Turks were in the midst of an epic expansion, and their giant fleet lay in Venice harbour.

Having already made inroads into Venice's great empire,

the Turkish warships were now striking at its very heart.

For Leonardo, this was the perfect opportunity to find a buyer for an unusual secret weapon.

So he came here to the Council of Venice, not as a painter, but as an inventor.

The Venetian councillors were the real power behind the ruler, the doge.

Their authority was absolute. They had the power of life and death.

Leonardo's scheme must have seemed the most bizarre they'd ever heard.

You live in a city of water and that water is your greatest asset.

It is my opinion that the Italians will not defeat the Turks fighting them in a conventional manner,

but with these designs, you can create a new kind of army - an underwater army.

Men as agile as fish, with armour adapted to underwater travel

and with a constant supply of fresh air, such as this.

These designs allow your army to approach the enemy from underwater

to drill great holes in the ships, sinking the ships, and thus the battle is won with minimal losses.

I'm always fearful of describing my methods.

Men will rush to make the ocean floor yet another field of battle.

So why go to the Council?

The Turkish fleet lies just off the Venetian coast.

What is one to do?

And will they try so bold a scheme?

I doubt it. They'll probably think I am quite mad.

There is no doubt that Leonardo's idea of a crack squad of underwater divers

was far-fetched and full of practical problems.

But if had been tried, might it just have worked?

Could he have mastered underwater diving hundreds of years before anyone else?

We decided to find out.

The diving suit is being stitched together using traditional methods and materials.

Pigskin leather has been treated with fish oil to make it water-resistant.

The water just beads right off.

Our suit was designed by Scott Castle, a former counter-terrorist officer,

and world-record holder for the longest dive.

It'll be worn by Jackie Cousins, who dives with giant squid for pleasure.

We could make the whole suit out of this if it has good waterproof qualities.

A reinforced helmet has to be made to prevent the mask squeezing and bruising Jackie's face

as the water pressure increases the deeper she goes.

The hood will need glass lenses - a material Leonardo would have had easy access to.

Venice was the world capital of glass production in 1500.

Leonardo's plan was to make the long snorkel from hollow pieces of bamboo.

Above the surface of the water emerges the mouth of a tube

by which the diver draws breath,

supported on wine skins or pieces of cork.

The lengths of bamboo are joined together with a pigskin sheath.

But had Leonardo considered the effects of water pressure?

As I inhale, which simulates the outside water pressure...

It just collapses. I'm going to suffocate. Yeah, well, not me!

The drawing shows Leonardo knew enough about water pressure

to put a spring inside the sheath to stop it collapsing.

But could his grasp of physics in the 1500s enable him to design an underwater breathing apparatus?

Go ahead and you plug it...

Right, so it's keeping it open and giving it flexibility as well. Exactly.

So it didn't fully collapse,

which means that perhaps Leonardo had more knowledge of water pressure than we thought.

We decided to try out the suit in the safety of a swimming pool before bringing it to Venice.

A cork float holds the bamboo snorkel out of the water.

But a snorkel device such as this

won't allow Jackie to go very deep before the water pressure makes breathing uncomfortable.

That was completely amazing!

I was really enjoying that.

It was good until you get to a certain level

and then suddenly it's really hard and you're really struggling.

The pain in your chest is here.

It starts to get really hard.

But just moving up a couple of inches makes all the difference and you breathe really easily.

But with the diver only able to go down a few feet before breathing became difficult,

Leonardo's plan to walk along the sea bed would have been impossible.

Or had he concealed his solution?

Leonardo's scribbled instructions for all his devices are chaotic and fragmentary.

Perhaps they are also deliberately misleading.

In his notebooks, Leonardo writes that it would be dangerous if this design got into the wrong hands.

Was that level of secrecy something that was familiar at that time?

There are two ways of looking at the secrecy. One is what we call intellectual property.

There's not much point

in selling your services for a lot of money if your secrets leak out.

And the other is a moral one - do you want everybody to know this device that can cause such havoc?

I have been asked many times to describe my methods for remaining underwater

without sustenance.

But I refuse on account of the evil nature of man who could practise assassination on the sea bottom.

Scott and Jackie are going to test the diving suit in the Venetian lagoon,

where Leonardo intended it to be used 500 years ago.

We know the concept as he sketched it is limited and dangerous.

So Scott has to work out what Leonardo didn't tell us.

The cork float is way too complex to just be a cork float.

There has to be more to it.

As I looked at the sketch,

I started to realise that Leonardo put some stuff on the drawing that wasn't correct.

He was trying to hide something and I'll tell you what I got.

These holes up on the top,

I don't think they were up here. I think they were down low.

If they were low, there'd be a massive air chamber inside.

The diver still used it as a snorkel,

but they can also grab it and pull it down.

Eventually, gas always goes > to the least amount of pressure.

So it turns into a compressed-air diving system.

Jackie now feels more confident as she takes the plunge.

It's very snug round the hips!

You lifted me right up!

If Scott is right, this could make it possible for her to walk across the sea bed.

So all I have to do

is pull these ropes down to get fresh new air into the hood.

I was looking through some other pieces of paper here. He had bellows here.

There's a flexible hose coming off.

So if we were to use the bellows,

you're giving compressed air to a diver.

So Jackie makes the dive into the depths of the Venetian lagoon.

But can she fulfil Leonardo's dream of walking along the sea bed?

The diving suit is a triumph.

Jackie is able to walk along the sea bed, just as Leonardo described.

An underwater army.

Men as agile as fish, with armour adapted to underwater travel

and with a constant supply of fresh air such as this.

Even today, there's a touch of James Bond about Leonardo's plan.

So heaven knows what the Venetian worthies would have made of it.

They must have considered him a little over the top.

In any case, his revolutionary plans were never needed. Attacked elsewhere in their empire,

the Turkish fleet turned round and sailed away without a fight.

And as for Leonardo, the Venetians sent him away without a single ducat for his pains.

But alongside the diving suit,

are hundreds of eclectic ideas which seem to stand outside their time - catapults,

printing presses, spring-driven motors and windmills.

Artillery designs more 19th-century than 15th.

His deadly-looking finned missiles look more like the high-explosive shells of modern times.

They give us a fascinating insight into his daily life and thoughts.

Alongside the inventions and drawings are shopping lists,

notes of the costs of his household, detailing his permanent cash-flow problems.

His need to earn a living meant he often had to keep very strange company indeed.

Leonardo frequently mentions his horror of war and man's inhumanity to man,

but his ambition now brought him, in the winter of 1502,

to the door of one of the most brutal and bloodthirsty tyrants ever known.

As the rulers of the various Italian states were engaged in a battle for power,

Cesare Borgia had threatened them all with his growing ambition and military cunning.

Leonardo was very pragmatic.

Leonardo wanted to be free to be Leonardo

and for that he needed money.

So he took commissions he didn't really want.

Often, he wouldn't finish them.

He got involved with some pretty bad people.

The worst was Cesare Borgia, who was an absolute monster.

He was the most hated, the most feared and the most envied man of his day.

Cesare Borgia famously murdered his brother,

had incest with his sister

and he'd poison or garrotte his dinner guests.

Not bad, is it? The perfect place for a cosy dinner party.

The situation, on paper, looks alarming, I must admit.

Famously reclusive, Borgia even allowed Leonardo into his rooms

and the drawings which Leonardo made suggest a close relationship.

Borgia, I think, is an interesting character, because, I think, he's very much like Leonardo.

I think that he's a charismatic figure.

He's very ambitious.

Leonardo is fascinated by that.

My men fear me, da Vinci,

but they also love me.

And yet how many of them know me...

..know really what kind of man I am?

-What do you think?

-He smiles, but I've come to realise that with men like that,

-it's bad when they're hostile and worse when they're friendly.

-So why do we stay?

We...we stay because we have to eat. You especially have to eat.

It was a critical moment in Borgia's brilliant career.

His land and his life were under threat.

Del Michelotto is to be despatched to raise 1,000 infantry,

to take a message to Ugo de Mancardo.

He was desperate for all the military ingenuity he could buy.

Characteristically, at exactly the right moment, Leonardo produced a trump card.

It was probably the most effective weapon any military commander could hope for...

a map - the first detailed and accurate plan of Immola, Borgia's stronghold.

'You show any person...'

in the late 15th century a map - it's a strange, magical object.

"Look, here is your territory!" That's stunning for people.

It's remarkable.

Whoever owns this map owns the city itself.

It's as if you could fly,

as if you could fly above the city like a hawk!

How have you done it?

I paced out all the greater distances, my lord, precisely, so as to be accurate...

With none of the instruments to measure this maze of streets,

it must have been a daunting task.

He paced every single field, every single street.

He measured everything and really pushed forward ideas of surveying, how you survey land.

We never see that level of precision, that level of detail,

but also that level of beauty in mapmaking for many, many years after that.

Borgia had appointed Leonardo his chief engineer.

He gave him a unique level of power and his personal protection.

Leonardo would now undertake epic projects of civil engineering.

The draining of huge tracts of land, the fortification of towns.

He was even planning to reroute the River Arno.

WOMAN: It gives him a freedom to order people about, to say, "Move that river here!

"Let's do it this way!" because he's got a single mind to work with.

We may say Cesare Borgia's was a twisted mind, but, for Leonardo, he was a guy who could get things done.

But he was still Cesare Borgia.

What happened next isn't clear.

Leonardo may have become close friends with one of Borgia's lieutenants Vitellozzo,

who'd fallen foul of his unpredictable lord.

Vitellozzo excuses himself. Apparently,

if I were to agree to see him personally, he could justify himself absolutely

and make me understand that past actions were not meant to offend me.

So Vitellozzo was invited to dinner and told he would be made very welcome.

Leonardo went back to Florence two months later.

Whether his friend's death had persuaded him to leave Borgia's service we just don't know,

but it must've seemed an appropriate time to go home.

As always, he was looking for the big commission that would bring him fame and fortune.

The monastery of Santa Annunziata had commissioned him to paint a Virgin and child with St Anne.

His original drawing, or cartoon, for the painting is now lost,

but this version of it, done a year or so later, gives an idea of its strength and beauty.

The cartoon was even put on public display and drew large crowds to view it.

It was said, "as if to a sacred festival."

Leonardo's private obsessions and researches go on.

His biographer, Vasari, describes one of his habits.

Another bird. The stallholder will think you're mad.

Oh, no, no. He's been paid what he asked for the birds.

A bird should be able to do what its nature dictates...

which is to fly.

So should a man if he has a mind to take wing.

Once you have tasted flight, you will forever walk the world with your eyes turned skyward.

For there you have been and there you will always long to return.

The feeling is all that Leonardo ever imagined.

But could he possibly have achieved it with any of his designs?

There are pages packed with research and ideas.

This must have been his most absorbing passion.

-Did he believe it was possible?

-He was of a generation of artists who were interested in fame

and he said, "This will bring fame to the nest from which it was born."

And the age-old human quest to get ourselves up there is just amazing.

If he could have achieved that - he has no worries about fame now! -

then his fame would have been assured.

Leonardo envisaged a number of designs for flight

including an ornithopter - a machine powered by man flapping great wings like a bird.

This, as a flapping mechanism, is simply not going to work

and Leonardo began to realise the power-to-weight ratio... You couldn't get up by doing that.

Another of Leonardo's concepts is said to have inspired Sikorsky

to lead the world in helicopter design

and it seems Leonardo did have a fantasy of one day trying out these machines for himself.

But perhaps the most achievable at the time was this intriguing design

for what is apparently the world's first controlled glider.

This is unusual in that it's a kind of abstract design.

Now you have to ask where this came from.

I think he'd looked at leaves and the sort of seeds that are aerodynamic.

And at one point there's a sheet in which he looks at a rectangular piece of paper descending like this.

He realised that these shapes themselves had certain qualities.

We found two brave experts willing to build and try out the design.

-Is there still risk in man-powered flight?

-There is phenomenal risk.

Medieval flying machines - it's got to be dangerous.

We'll be careful!

Most of the pioneers of flight injured or killed themselves

-because it is so dangerous.

-Well, good luck!

-Thank you very much!

But even Leonardo was well aware his inventions could be lethal.

Note. Make trial of action machine over water, so if you fall, you do not do any harm.

Simon begins by constructing a model based on Leonardo's plans.

The man places his feet at "M" and chest at "B".

The wind, blowing along line "H",

may lift "H" more than is deemed convenient.

In this case, the man should pull string "S".

Simon's wondering just how good was Leonardo's understanding of aerodynamics.

The first step is to test the model in a wind tunnel.

We're looking for evidence of lift as the oncoming air collides with the glider.

It looks encouraging as a vortex spirals upwards from the wings - a phenomenon Leonardo was aware of.

The bird will rise on high by means of a circular movement in the shape of a screw.

By now, Simon was convinced the glider had a chance.

So he went on to build a full-size version.

He's making the framework out of bamboo, which he steams into shape.

For the sail, he's chosen a man-made cloth.

This is less likely to be ripped during testing than the silk or linen Leonardo might have used.

The big day has arrived.

It couldn't be more perfect - warm Tuscan sunshine and a light wind.

The mood is buoyant as I join the team.

-Are the teeth chattering?!

-No, I'm not really nervous. I'm hopeful rather than nervous.

I'd like it to fly and I'd like to...well, at least live MY dream,

which is to fly a machine that was designed 500 years ago.

1, 2, 3...

It's a dangerous business testing flying machines.

If he crashes from 10 metres above ground, he risks serious injury.

It's known in the trade as the Dead Man's Curve.

-It wasn't much of a flight!

-No.

-Oh, dear!

-Fortunately, nothing broken. We can try again!

Bugger!

I crashed it again!

The glider was definitely unstable, so we went back to Leonardo's notes for inspiration.

Look at how birds fly...

..how they use both their wings and their tail

to stop them falling.

'If Leonardo had got as far...'

as testing this and found that it was unstable,

it would be natural for him to say, "Let's have a tail on it."

Would the tail make the crucial difference?

It was now all or bust. Robbie's raised the stakes. He's going to fly off a much steeper hill.

It'll give him more chance of getting airborne,

but if he crashes, the consequences will be grave.

..2, 3!

CHEERING

Well done, Simon!

Well done, Robbie!

'It's the first time a Leonardo flying machine has successfully taken to the air - a triumph!'

Well done, guys. That was amazing!

His return to Florence in the early 1500s wasn't the overwhelming triumph he'd hoped for,

although his famed cartoon of the Virgin and child with St Anne would turn into a beautiful painting,

a dreamlike image of maternal love.

And in 1503, he began work on a portrait that would one day become the world's most famous painting,

the Mona Lisa.

He would rework it obsessively for the rest of his life, taking it with him wherever he went.

Now, as he began to re-establish himself, a new talent appeared on the scene.

In 1499, a marvellous sculpture by an up-and-coming young artist had been unveiled in Rome.

The Pieta was immediately hailed as a work of genius.

Its maker would become Leonardo's lifelong rival.

He was 24 years of age

and his name was Michelangelo Buonarotti.

There was rivalry and enmity.

They could not have been more different.

I look around the painter's studio. I speak of the very best painters, of course.

His home is clean and filled with works of art.

There is no noise, no hammering, only the most pleasurable of pursuits and agreeable of friends.

Leonardo was elegant, well-behaved, a courtly man.

Interested in everything, with a shrug of the shoulders at failures.

Michelangelo - this extraordinary zealot in both religion and art.

A deeply-troubled, deeply-driven figure.

The sculptor, on the other hand, hacks away at his marble like a mechanic, with brute force,

his face plastered with filth.

RONA GOFFEN: Michelangelo was a slob.

He bathed infrequently, had terrible manners, was cantankerous and grouchy and nasty and sarcastic.

He's also known to have worn these dogskin leggings,

which he never removed. And at the end of each winter,

he'd peel them away, taking his flesh with them, because they'd grown into his skin.

The sweat mingles with the dust. It all turns to mud. He has a very filthy house because of that.

He looks like a baker at work!

No real painter thinks of sculpture as anything less than painting. They're from the same source!

They're both divinely inspired!

But even if Leonardo thought sculpture the lesser art,

he wasn't going to turn down the biggest commission of the times - a statue of David, the giant slayer.

The city of Florence had got hold of a vast slab of marble

and Leonardo waited patiently to be awarded the commission.

But Michelangelo had got there first.

There are two artists who could design a monument good enough to honour this proud city.

At least, two artists who could start the work. But only one has proved he can finish it.

So you must ask yourself - do you want the monument finished

or are you prepared to let the marble lie undisturbed for the next ten years?

Michelangelo won the commission and laboured at it for three years.

It was a triumph.

So, round one to Michelangelo, but then Leonardo makes his move.

Michelangelo wants the statue out here, in front of the town hall, where it'll really get noticed.

A committee is formed to decide where it should go

and a variety of prominent locations are considered.

However, who should be sitting on the committee charged with this decision but Leonardo da Vinci,

who thoughtfully suggested that the statue should be placed over there, out of the way.

He was, of course, over-ruled.

And Michelangelo's David was given pride of place right in the heart of the city

where he stands, in Michelangelo's words, "proudly in the blaze of the piazza".

David was to become the most famous statue in the world,

but his creator would never forgive Leonardo for the slight.

By 1504, the relationship between Leonardo and Michelangelo had declined to the extent

that they could hardly pass in the street without grimacing.

We actually have an account of one famous public squabble

left by a friend of Leonardo's who'd witnessed it.

Here comes Michelangelo. Ask him!

-Explain Dante's love for pagan gods.

-YOU explain, horse modeller! You've an answer for everything.

'Michelangelo was not only a poet but also he was famous for his knowledge of Dante...'

and it was natural to say, as Leonardo did, "Michelangelo will explain it."

Michelangelo took umbrage at this.

You've an answer for everything, except how to cast a statue in bronze.

Will you ever finish ANYTHING ever again?

'This was a rotten thing to say. It was very rude, very offensive

'and Leonardo was red in the face. He was blushing with embarrassment.'

And soon, they really did have something to fight about.

The new powerbrokers in Florence invited Leonardo to paint a battle scene 60ft across in this building,

the town hall.

But there's a twist.

They then asked Michelangelo to paint another battle scene alongside it in the very same room.

As if this wasn't enough, the man who set up this battle of battles was the infamous Machiavelli,

the godfather of political spin.

He was Cesare Borgia's right-hand man and, supposedly, Leonardo's friend.

Leonardo worked feverishly, determined to achieve spectacular effects,

to prove something. He immersed himself in all the detail of battle and the psychology of men at war.

How to capture the hell of war, Salai?

Smoke mingling with the dust-laden air.

Arrows flying in every direction.

The conquerors bearing down on you,

their hair streaming in the wind.

Some of them shouting, some of them with teeth apart, their eyes brimming with terror.

Show the fallen corpses covered with mud. Others in a death agony, fists clenched, limbs distorted.

Show men fallen in a heap on top of a dying horse

and see there is no part of the ground that is not trampled and stained with blood.

While Michelangelo is in his studio doing one drawing,

Leonardo's actually, for once, getting a move on! He's made the cartoon, got the scaffolding up

and he's doing the fresco.

-But things began to go very wrong.

-CLAP OF THUNDER

On Friday, at the 13th hour,

I had just picked up my brush when the great storm began.

The church bells rang the alarm.

Day was transformed into night as the rain poured down - water everywhere.

The cartoon began to come apart piece by piece.

It was a bad omen and there was worse to come.

Leonardo's great Battle Of Anghiari should be here and Michelangelo's battle scene alongside,

but Leonardo decided to experiment.

He made a fatal decision to use oil on plaster.

We believe it's because he got a bad consignment of linseed oil.

This is the great tragedy of the career,

because he's pushing the limits of what he can do as an artist

and what he can do with paint further and further.

And the result, of course, is the materials just aren't up to it.

The painting he'd begun soon started to run and seemed to be melting off the wall.

In desperation, they lit fires under the fresco

in an attempt to set the paint and save the painting.

But it was too late.

So if you think the Battle Of Anghiari doesn't live up to Leonardo's grand plan,

you'd be absolutely right.

It isn't even his. The picture that's here today is by Leonardo's biographer, Vasari...

a far better writer than he was a painter.

But he leaves an intriguing clue.

In one corner, he's written "cerca trova".

"Seek and ye shall find."

Some people believe that somewhere in this room there are fragments of Leonardo's long-lost masterpiece.

Michelangelo, by the way, never finished his fresco, either.

He completed the cartoon for it, but he was called back to Rome.

So ended this strange battle of the giants - the battle that never was.

Leonardo would never be awarded a major commission again.

Now, left behind in Florence and with time on his hands,

he immersed himself once again in his life's other great project - his work as a scientist.

Over the next decade, he ranged across anatomy, geology, botany, medicine, geometry.

Apparently trying to master them all, learning and absorbing everything and drawing it.

And yet he had a reputation as a flake.

Well, his reputation as a flake was

that it's almost a surgical mind.

What's in front of you, it's the most important thing in the world.

Then when it's over, it's over and the next thing becomes the most important thing in the world.

It's a free-associating mind. "Here is work that fascinates me.

"I will work with it till it stops fascinating me, I'll stop and go to another thing that fascinates me."

So over short periods of time, you don't get much done,

but over a long period of time, you get a great deal done.

Now he would turn his attention to a whole new area of investigation.

And again, it would require him to break the rules.

It was at this hospital at the Santa Maria Nuova monastery

in the early 1500s that Leonardo took the first steps towards a ground-breaking discovery,

a discovery medical research would only catch up with in the mid 20thC.

When he started studying anatomy, it was only so he could understand muscle and movement, and so on.

But he soon became intrigued by what went on below the muscle layers

and, in fact, became the very first person to dissect the organs of the body.

At this time, anatomical dissections were occasionally allowed by the Church.

The bodies of convicted criminals were dissected by surgeons

who were watched by artists and students.

Given the conditions of the time,

few would have been willing to do the gruesome work Leonardo now carried out.

I want to go home. It's freezing!

Come here.

-'What was the atmosphere like in the dissecting room?

-Oh, it was dreadful in the dissecting room.

'There was no way of preserving bodies at the time.

'Within 48 hours, there was a tremendous stench,

'pieces of the body were decaying.

'The most important instrument that one had was one's bare hands

'with long fingernails that were used to do a lot of the dissectomy.'

Why must we spend our night in the company of corpses?!

Yeah, well...

most men can't make the journey they need to take to find out the truth.

The stench of death turns their great stomachs and they're sickened by the blackened organs.

But if you want to follow where the light of truth leads, you have to get through all this.

The bodies come back and haunt me in my sleep.

His dissections were convincing him more and more that man is a wonderful piece of machinery.

He conceived of the bones of the arms and of the legs as levers.

And lines of force, namely the muscles, worked on the levers.

So he could demonstrate exactly how you turned your arm

and why you were able to turn your arm.

This led him to his most audacious conclusion - that he could create an automated machine

with a life of its own.

Leonardo married his fascination for anatomy with his passion for mechanics

to create the world's first humanoid robot.

We've asked NASA engineer Mark Rossheim to see if he can bring Leonardo's scheme to life.

These are drawings of Leonardo's robot knight. These are fragments.

-This is the torso...

-Yes.

..the shoulder. Here is a detail of the arm.

This is a cable-operated system with pulleys.

They transfer the motion from the cables into a rotary motion for an elbow or an arm.

You've done a virtual model.

Yes, we've done a virtual-reality reconstruction of the robot knight.

We've taken Leonardo's anatomical drawings and translated them into mechanics.

He left these really interesting drawings showing how the forces moved in the human joints.

He would substitute cords. They're called cord diagrams.

By looking at those, I was able to plot the paths of force.

We were eventually able to construct joints and actual levers,

so you get the impression of muscles moving, of flexing,

just like a bodybuilder.

We've done a virtual-reality, uh...animation of the machine

and here you see the pulleys of the cable system operating the visor.

It's going down in the body. This is what allows the robot to stand up.

And so understanding how the human body works mechanically and how it can create gestures

is just a foundation principle of his art.

There's a famous line where he says, "Nature doesn't use counterweights." Nature doesn't build animals,

or humans, like grandfather clocks. His tools were very limited.

He had to use winches and cables and pulleys.

Take a bow, robot!

At the time, the robot was designed as a stunning party piece.

It would probably have been set up in a grotto as a climax to a court entertainment,

so a patron could impress guests.

Leonardo was kind of a special effects master of his day.

It would have had kind of a Stephen Spielberg effect.

THEY LAUGH

I love it!

Well done! ..Well done!

His anatomy told him something of what he wanted to know about this marvellous machine, the human body.

But he wanted to discover where man's soul might be found,

the sensus communalis, the seat of reason and imagination.

He wanted to read the mind of God.

There was a new Pope in Rome - Leo X.

The Vatican was summoning major artists from all the Italian states to create great new works.

Michelangelo was already firmly ensconced here as a favourite.

But if Leonardo expected to be greeted as a hero of this new age, he was to be disappointed.

This is not the time to have him at the Vatican,

this painter who never finishes anything he starts.

He has asked for an assistant. Choose him well.

Leonardo was provided with a studio, but, it seems, no serious work

and the German assistants he was given appear to have been spies.

He describes the wickedness of a German deceiver who spreads rumours about him throughout the Vatican

and his insistence on continuing his studies in anatomy

were giving his enemies plenty of grounds for suspicion.

He is in and out of the hospital. I fear he is dissecting also good Christian people.

The old man told me he's lived for over 100 years

and that he's had no bodily ailments, apart from weakness.

And then, with nothing apparently amiss...

..he died the sweetest death.

'He looked at the man's vessels...'

Hold this here!

..and realised that the inner part was obstructed. It was like shale inside of a pipe.

And he reasoned that that's why old people die slowly, why their extremities shrivel,

because the blood isn't getting to them.

At about the same time, by coincidence, he dissected the body of a two-year-old boy.

And, not to his surprise, found that those arteries were straight and soft

and nothing was obstructing them.

So he said, "That's the reason people die of old age.

"The arteries are becoming closed off and obstructed."

He discovered, in the early 16th century, hardening of the arteries, arteriosclerosis.

'Then he said, "But why does this happen?

' "Something happens over time." '

Then he lit on it. He said, "There's too much nutrition in the blood.

"There's something in the blood that precipitates out, that comes out of the blood

"and deposits itself on the inside of the arteries."

Except for the word "cholesterol", he had made a 20th-century discovery!

Given the controversial nature of Leonardo's work,

his enemies had no trouble finding evidence to condemn him.

The drawings were proof enough,

but his mirror writing even suggested witchcraft to those out to denounce him.

He's not only dissecting the bodies of the dead.

He then that of a woman with child.

Then this - writing which can only be read with a mirror.

You think this is to conceal the true nature of his work?

We are fearful of necromancy.

There is no limit to the investigations of the Florentine.

Fetch Leonardo da Vinci.

His Holiness requires your presence.

Your Holiness.

You have been accused of witchcraft and necromancy. You spend your nights with the dead.

I will not tolerate the Vatican being used as a charnel house.

Leonardo da Vinci, you will not continue your unholy practice.

You will not bring shame upon the Vatican or on the name of God.

He had by now completed an incredible amount of work

which he describes with pride.

120 chapters composed by me will give judgment

in which I've been impeded neither by avarice nor by negligence, but only by time.

Farewell.

Tragically, even his anatomy would be another heroic failure,

lying undiscovered for centuries while the rest of the world caught up with Leonardo da Vinci.

His contribution has no significance because it was lost. It affected nobody and nothing.

When it was rediscovered, his contribution in anatomy, all of these things had been identified.

Around this time, he wrote in his notebooks...

Tell me, have I done anything of worth?

Tell me if anything was ever done.

But unknowingly, he'd already provided the world with his legacy.

He took her with him as he left Rome. She accompanied him for the next 15 years

and she was beside him when he died.

And after much of the world had forgotten him,

it would be the Mona Lisa who'd cause him to be rediscovered.

She would carry his name through the centuries to a new audience for whom curiosity was not a crime

and where free thinking was applauded.

It would be her inexplicable smile

which would hint at the mysteries Leonardo had uncovered in his search for everything.

Subtitles by Graeme Dibble & Alison Semeonoff - BBC Broadcast, 2003