Secrets of the Mona Lisa (BBC)

The Mona Lisa...

Bewitching...

Seductive...

World-famous.

In the minds of millions, she is the ultimate work of art -

endlessly photographed and admired.

Yet, behind the enigmatic smile,

she remains a mystery.

Who was she?

Why was she painted?

And what has made her the world's most famous painting?

After 500 years in the spotlight

the Mona Lisa is finally giving up her secrets.

Centuries-old documents are at last revealing long-forgotten truths.

This is wonderful. Ooh! I've got a shiver down my spine.

State-of-the-art technology is taking us

beneath the painted surface

to decode astonishing new evidence.

That's extraordinary - wow!

That's quite a big discovery, isn't it?

Yes, it is.

This investigation -

the first full forensic examination

of the latest discoveries -

takes me round the world in the hunt

for the truth about Leonardo da Vinci's masterpiece.

With exclusive access and some extraordinary encounters...

The first impression when I came in was...

I did well not to jump backwards in shock!

These revelations will change everything we thought we knew

about history's most enigmatic work of art...

That's great. So we just made a new discovery.

And unlock the secrets of the Mona Lisa.

All of this together marks an extraordinary moment

in the history of art, but more than that,

this is quite simply one of the stories of the century.

500 years ago a man painted a woman.

The man was Leonardo da Vinci -

artist, inventor, genius -

and the result of his work

was the inscrutable portrait we now know as the Mona Lisa.

It's a masterpiece.

But one of the few works he actually finished.

So what draws us to the Mona Lisa?

She's not a famous monarch or a legendary historical figure.

We know hardly anything about her.

So what is it about this picture that's gripped the human imagination

for so many centuries?

I want to begin my investigation

by comparing notes with a detective

who's been on the case for more than 30 years.

One of the world's leading experts on Leonardo da Vinci,

Oxford professor Martin Kemp has spent much of his life

obsessed by the mystery of the Mona Lisa.

What do you think is the key to the Mona Lisa's extraordinary

stature as without doubt

the world's most famous painting?

Well, there has to be something inherent in the picture.

Some things are famous for being famous.

We live in an age of celebrity

and lots of celebrities are famous for being famous,

but they're not going to last.

This has gone on for ages.

It is just extraordinary.

And you've got this sense

of something which is beyond pigment

and beyond a good likeness and being beyond a face,

and it just has that totally uncanny living presence.

It was very daring at the time

for a woman in a portrait to look at you.

You know, women's portraits simply didn't do that,

and I think the ambiguity, the... the tease - the visual tease -

is something that Leonardo absolutely cultivated.

Look at the Mona Lisa

and you can't help feeling there's more going on than meets the eye.

If her teasing smile's a question mark,

the painting's a riddle.

What makes a human being live and breathe?

What forces govern the world we live in?

Leonardo thought about these questions as deeply as anyone.

And behind this breathtakingly lifelike image,

lay years of investigation into spheres of knowledge

Iike geology and anatomy, some of which

were forbidden by the church.

Tantalising evidence for the research that went into the Mona Lisa

Iies hidden in Windsor Castle.

Amongst the gems of the Royal Collection

is an intriguing clue to the genesis of the portrait.

A page from what might be called the real da Vinci Code.

If you want to see, or have some sense of,

just how much work there was behind the surface of the picture

then this is a great place to start.

It's a sheet of drawings by Leonardo's own hand.

And what does it contain in faint outline?

Look here...

It's a bit like the Cheshire Cat,

it's the Mona Lisa's smile

without the Mona Lisa attached.

It may well have been Leonardo's first gropings towards his idea

for the painting.

It's a series of studies of the human mouth,

the motions of the mouth.

How the mouth puckers.

How the mouth...bares its teeth.

You have a very strong sense that for Leonardo

every picture is a kind of encyclopaedia entry

and this is just that part of it

dealing with the mouth.

It's just the tip of the iceberg.

The Mona Lisa is the work into which Leonardo poured everything he knew

about humanity and the world that surrounds us

with its ceaseless play of light and shade.

But there's a mystery there, too.

And it's staring us in the face.

Who is the woman with the enigmatic smile?

It's a question that has fuelled all kinds of speculation

ranging from the ingenious to the crackpot.

She's a pregnant mother-to-be.

She's a prostitute.

She's even a man in drag.

But if you look beyond the theories

there are clues to her true identity.

Florence, 1500.

After many years away

Leonardo da Vinci has returned

to the city of his youth.

He's come back to work on ambitious military projects

for powerful men.

He says he's too busy to paint portraits of wealthy aristocrats

who clamour after him.

Yet according to one writer

Leonardo somehow finds time to paint the portrait, not of a noblewoman,

but of a humble merchant's wife called Lisa.

It was here that Leonardo da Vinci

began the most famous painting

in the world...

And it was here that Giorgio Vasari -

the inventor of the very idea of the Renaissance,

the author of the very first book about the Renaissance -

produced Exhibit A in the case of the Mona Lisa.

The very first account of the painting.

Who was she?

She was the wife of Francesco del Giocondo, a rich merchant.

He commissioned Leonardo to create her portrait,

and Leonardo responded with a picture, says Vasari,

"So miraculously lifelike

"that it seems to be made of flesh, not paint."

"Leonardo," he says, "wanted to avoid the melancholy

"that dominates so many other portraits

"so he employed musicians, entertainers, buffoons

"to keep her amused."

So there you have it -

the wife of Francesco del Giocondo,

and the smile caused by

entertainers hired by the artist.

An open-and-shut case.

Or is it?

How can we be sure that Vasari was right,

and that Leonardo did indeed paint Lisa del Giocondo?

After all, Vasari wrote his account 30 years after Leonardo's death,

and although he did his homework here in Florence,

he never disclosed his sources.

So could it just be hearsay?

Some inaccurate local legend?

For centuries there was no way of telling.

Then suddenly new evidence emerged

from a completely unexpected source.

In 2006, a research scholar

working in the University Library of Heidelberg

turned up this.

What it is, is a page from a copy of Cicero,

the ancient Roman author,

a book that was once owned

here in Florence by a man called Agostino Vespucci.

And not only does it have Cicero's text,

but it's got Vespucci's commentaries

and this particular passage is crucial.

Because in it Cicero is discussing Apelles,

the ancient Greek artist,

and his remarks prompt Vespucci to make his own notes -

his marginal note -

and what he writes is a kind of bombshell

in the history of Leonardo studies.

He says "Apelles, ha!

"He did just the same thing as Leonardo

"in his portrait of Lisa del Giocondo."

And best of all, there's a date -

"October, 1503."

So this was written almost immediately after Vespucci

must have seen the portrait of Lisa del Giocondo

in Leonardo da Vinci's workshop.

This is gold dust, and it proves

that Vasari was definitely right in at least one sense all along.

Leonardo definitely did paint a portrait of Lisa del Giocondo.

There you have it.

Independent testimony from a man in Florence in 1503

who probably saw the picture still wet on the artist's easel.

But now there's another question.

Why did Leonardo paint Lisa

when the great and powerful couldn't coax a picture from him?