-Grace Kelly.

The Philadelphia girl next door who turned her back on her millionaire father... -He didn't like her.

And there had to be something sadistic about that.

-She was desperate to get away from the strict, rigid family life.

-...to become one of the most famous women in the world.

-She was beautiful.

She was classy.

She was elegant.

-You could not take your eyes off her.

-She was an Oscar-winning actress who lit up the silver screen with magnetic performances.

A glamorous fashion icon and global trend-setter.

-People wanted the Grace Kelly look.

-She really perfected the embodiment of a certain kind of Hollywood glamour.

-She could command millions.

-Grace Kelly made people money.

That's the bottom line.

-Some people estimate Grace Kelly's value today to be worth around $100 million.

-She played hard... -Grace did develop an image as being a bit of a husband stealer.

-I think Grace Kelly just liked sex.

-...and negotiated harder.

-She was savvy.

She knew what she wanted.

-She was one of the highest-earning women in America, if not the world.

-But her big gamble... -It's hard to know, really, what was going on in her head.

-...to marry a playboy prince... -No longer Grace Kelly, but Princess Grace of Monaco.

-...ended her career almost overnight.

-I was just beginning to glimpse into what it was all about when I stopped.

-And whilst she appeared to live a lavish life of opulent luxury... -Together, they are planning the future of the place which wealth has made a paradise.

-...and generated millions for the Grimaldi royal family... -Rainier saw that she could put Monaco on the map.

-...was it just a gilded cage?

-Will you continue with your career?

-Well, that decision will be made by the prince.

-A princess is not about expressing your desires, about doing what you want.

It's about serving the crown.

-When she died, personal papers reveal Grace had just $10,000 and a ramshackle cottage in Ireland.

-Grace Kelly should have amassed a fortune worth millions of dollars.

-Now, for the first time, wealth investigator Gemma Godfrey... -This is a copy of Grace Kelly's will, and it's fascinating.

-...reveals the secret of what happened to Grace Kelly's missing millions.

♪♪ ♪♪ -November the 12th, 1929.

A star is born on America's East Coast.

Grace Kelly was the third of four children for parents Margaret and Jack.

From humble beginnings as a bricklayer, her father became a self-made construction millionaire and Olympic rower.

Margaret was a model and sports coach.

This good-looking couple would raise their family with the same drive and ambition.

-Grace Kelly's home life as a child was as part of a very competitive, physical, high-achieving family.

-The family ethic was very much about success.

-You got to be good at sports.

You've got to be good at songs.

You just had to be good, and her father was all these things.

So he expected a lot out of his kids.

-And her siblings followed in the family footsteps.

♪♪ John Junior served in the U.S. Navy before turning Olympic oarsmen and professional sportsman.

Grace's sisters, Margaret and Elizabeth, were both accomplished athletes and worked as community volunteers for local charities.

It left shy, awkward Grace feeling sidelined.

-Grace's role in the family was not as the most successful one or as the most high-achieving one.

-Grace was the quiet, introverted one.

She was bookish.

It was said she always had a cold, and so no one expected her to have the kind of career that she had.

-But Grace did have financial privilege.

Home was a 4,000-square-foot mansion her father had built, complete with servants.

-The family of Grace Kelly in America would be considered upper-class.

-There was no rags-to-riches story about her, such as there was for other stars like Marilyn Monroe, Ava Gardner.

That just didn't apply to Grace.

-But money couldn't buy love.

In the shadow of her athletic siblings, Grace craved affection and warmth.

-Grace's mother was a tough woman.

She was a devoted mother, but it wasn't a fun, light, loving relationship.

-Jack Kelly was a bully.

She just wanted him to say she was good.

"You're okay."

He didn't even say that to her.

And there had to be something sadistic about that on his part.

And he didn't like her.

So this was something she carried with her.

♪♪ -Born into wealth, Grace Kelly should have inherited a generous slice of the family fortune.

So, did her difficult and distant relationship with her parents ultimately cost her dear?

♪♪ Gemma Godfrey is one of Britain's leading financial gurus.

She's handled billions for the super-rich and investigated hidden assets for the world's biggest companies.

But now she's taking on the mystery of Grace Kelly's missing millions, starting with unique access to Grace Kelly's American will.

-You can see why she signed it Princess Grace of Monaco.

It was executed on the 27th of May, 1975, which would have been seven years before her death in September 1982.

It says that it covers all of her assets in America, which would cover things like bank accounts, stocks, bonds, real estate.

But there are a couple of things here that strike me as really odd.

-Grace put her entire estate in trust to a Philadelphian bank.

But when she died, her mother, sisters, and brother were still alive.

She had three children of her own.

So why not bequeath her American assets to any of them?

-And then her will says that the value of her American assets is just $10,000.

That's roughly just $27,000 in today's money.

-As a Hollywood superstar, royal princess, and with a wealthy American family, Grace should have amassed a fortune worth millions.

The mystery deepens when compared with other Kelly family wills.

-So, I've managed to obtain a copy of the will drawn up by Grace's mother, Margaret.

She died in 1990, but this is the important thing here.

Her tax return shows the value of her estate was more than $2 million.

-And Grace's younger sister Elizabeth's will reveals a similar story.

-Her tax return shows that her estate was worth over $1.5 million.

-So why did Grace Kelly's family have American assets worth millions, yet she died with just a few thousand dollars?

♪♪ In her late teens, Grace decided to turn her back on the family fortune and blaze her own trail, on her own terms, in New York.

-She was much tougher than the males.

-She was savvy.

Grace was a savvy businesswoman in that she knew what she wanted.

-What drove Grace was wanting to become a great actress.

And that was what made her continually work and strive to improve her ability to emote, to improve her ability to create character and convey emotion.

That was what drove her.

That was what kept her going.

-Grace Kelly would become a Hollywood star, generating millions for the studios and sharing the billing with some of the greatest leading men of her generation.

So what happened to her multimillion-dollar fortune?

Grace Kelly had turned her back on her family fortune, determined to make her own money.

Wealth investigator Gemma Godfrey has been unearthing key documents that reveal how she became one of the highest-paid stars in Hollywood.

-I've managed to track down the details of the agreement that Grace Kelly signed with MGM Studios.

She made the studios a fortune.

-But when she died, Grace had just $10,000 to her name.

So what happened to her missing millions?

♪♪ Aged 18, Grace Kelly was on her own in New York.

She had enrolled on a $1,000-a-year acting program at the American Academy of Dramatic Art and was living in the Barbizon Hotel for $12 a week.

-She was desperate to study, to support herself, and I think to get away from the rigid family life that she had a home.

-It was opportunistic for her.

She went there and tried her luck.

-The drama school was expensive.

It was $1,000 a year.

Back in 1950, that was a lot of money.

-Starting out at the same time as Doris Day, Audrey Hepburn, and countless other aspiring stars, Grace would fund her dream of acting by modeling.

-Grace is dressed in a plaid sport shirt and matching shorts.

-And independent Grace was snapped up by the famous Robert Powers Agency.

-She paid for the Barbizon.

She paid for her lessons at the academy.

And I guess it was another way of saying to Jack, "Look.

Is this okay?

I'm not asking you for anything."

-She did advertisements for toothpaste, for beauty creams.

Advertisers and Americans at the time saw in her a kind of regal version of the girl next door.

-Grace wears a white classic wool polo shirt and beige linen Bermuda-length shorts.

-Working flat-out as a model, Grace would earn close to the equivalent of $300,000 today, small change compared with the millions she would go on to earn for brands like Dior and Hermès.

-She was beautiful.

She was accomplished.

But Grace Kelly made money.

-So, Grace Kelly visits New York designer Florence Lustig.

-Because the modeling agency was raking in a healthy 10% commission, too, helping them to gross annual profits of over $5 million at the time.

-She solves the problem by taking all three.

-But Grace had bigger ambitions than peddling the housewife's dream as a model.

Her true love was acting.

♪♪ She was paid a pittance for a series of provincial theater gigs.

♪♪ But in 1950, a performance in "The Father" opposite Oscar-nominated Raymond Massey netted her an award and led to her big-screen break.

Aged just 23, she was cast opposite Gary Cooper in a movie still hailed as the greatest Western of all time.

-She played the kind of puritanical wife.

She had no makeup.

She was kind of pristine.

-She's got this strength and this ladylike quality that the role demands.

♪♪ -I mean it.

If you won't go with me now, I'll be on that train when it leaves.

-Shot on a shoestring, "High Noon" was a huge hit, winning four Oscars and making $18 million at the box office.

Grace Kelly's name was up in lights, and the movie bosses took notice.

She was summoned for a meeting with the most powerful studio in Hollywood, MGM, and, at just 24, negotiated the terms of her first Hollywood contract.

Analyzing the fine print has revealed how much it was worth.

-It gave the studio the right to three pictures a year over seven years.

The agreement contained a $20,000 bonus if Grace completed three pictures in a year.

But MGM could also fire her with six months notice and also loan her out to other studios.

So, under the terms of the contract, Grace was paid $750 a week.

So over the seven years, Grace was set to earn $273,000, or the equivalent of $2.6 million today.

-But in return, Grace was forced to comply with stringent rules in a system solely geared to maximize the studio's profits.

-MGM could drop her at any time.

She could not step out of the contract, but they could drop her.

They would choose all of her films.

They would tell her everything that she was going to do.

They would fix her up on dates for publicity.

She would live a completely Hollywood lifestyle governed by them.

That was the system.

-But Grace was determined that her MGM contract would not be a straitjacket.

-She never bowed down to the studios.

Before she would sign her contract with MGM, she insisted that she could stay living in New York, that she could have time off to do theatrical productions.

She always stood her ground and was very strong in her negotiations, as a very young woman.

-Studio bosses soon realized that despite her youth, Grace Kelly had a head for money.

-She was savvy.

Grace was a savvy businesswoman in that she knew what she wanted.

-For all their trials and tribulations, Grace had learned a lot from her businessman father.

-What's fascinating is that Grace Kelly was Jack.

She knew how to do business.

Her father, if he had enough sense, would have seen that.

-1954 was a blockbuster year.

Grace starred in five movies and was declared Hollywood's brightest new star.

-One of the most important things that happened was her role in "The Country Girl" with William Holden.

-Her ability to switch from glamorous Hollywood fantasy to the reality of an alcoholic's wife in the 1950s secured her legacy as a great actress.

-She basically wore a cardigan and not much makeup, but she gives a fantastic performance as the kind of downtrodden, world-weary Georgie Elgin.

-Performance by an Actress.

-It won her the ultimate accolade.

-Grace Kelly for "The Country Girl."

-She won the Academy Award for Best Actress up against very tough competition, Judy Garland for "A Star is Born."

And it meant the world to her.

-I can only say thank you with all my heart to all who made this possible for me.

Thank you.

[ Applause ] -The Oscar win didn't just establish Grace as an acting legend.

It was a savvy investment in using the limelight for monetizing her style.

-It was certainly one of the most expensive Oscar dresses ever to be worn up to that point.

It cost just under £8,000, which in today's money is £50,000.

A floor-length, ice-blue, French satin.

It's a tight-fitted bodice, draped at the front.

-A global fashion icon was launched.

-Grace's look was a very natural and classic one.

♪♪ -And marked the beginning of a lucrative sideline where Grace was gifted clothes and gave the brand's profits a golden boost in return.

-Grace Kelly made people money.

That's the bottom line.

-Grace had become Hollywood's highest-paid female star.

-Grace was known amongst her friends for being a little bit on the frugal side.

Ava Gardner famously described her as being tight with a buck.

-But earning millions as a Hollywood star also meant lavish spending to match.

She took over an entire floor of a building on New York's Fifth Avenue, home to some of the most expensive real estate in the world.

Her rent was the equivalent of $6,000 a month today.

Grace also hired a top designer to redecorate and fill her new home with expensive French antique furniture.

So, with this kind of spending power, just how much money was Grace making at the movies?

-By 1955, Grace was earning $1,250 a week.

Now, we know that in 1956, MGM awarded her a bonus over $65,000.

And she was reportedly earning $250,000 a year before tax.

Now, if we take all of the earnings and the bonuses across those five years in Hollywood, Grace Kelly's total movie earnings could have reached $1.5 million, or the equivalent of $15 million today, earnings that appear to be entirely missing from her will.

-But this was small change compared to what her leading men were earning.

-Women have always been paid less in Hollywood than men have.

And I think that's still the case today, that women are routinely paid less than men.

Got a little bit better as her career progressed.

But she wasn't making anything like what her male costars made.

-Grace was paid $750 a week to make "Mogambo."

Heartthrob costar Clark Gable, the king of Hollywood, who would star in more than 60 films in his 37-year career, got six times more.

And even after Grace had won an Oscar, her weekly fee in Hitchcock's "To Catch a Thief" was less than 1/3 of the amount Cary Grant was paid.

He starred in over 75 movies in a 34-year career.

MGM also cashed in on their contract with Grace by loaning her out to other studios for a generous fee, charging Warner Bros. a 400% markup for Grace to star in another Hitchcock thriller, "Dial M for Murder."

-And you won't be able to take your eyes off the glowing beauty of Grace Kelly.

-And Paramount were charged a 575% markup for her iconic appearances in blockbusters "Rear Window," "The Country Girl," and "To Catch a Thief."

-In the process, Grace made the studios MGM, Paramount, Warner Bros., and United Artists a fortune.

In total, her films made more than $1.5 billion at the box office.

-Money on a scale that Grace herself would never see.

Grace Kelly was now a household name, but any hope that her father might acknowledge her achievement was mistaken.

-Even when she won an Oscar, he still didn't really seem to see that as the pinnacle of success that it clearly was.

-He just rebuffed her.

He rebuffed her his entire life.

-"Mogambo," the new word in motion picture entertainment.

-But it wasn't just her father.

Grace was also troubled by rumors of torrid affairs with many of her leading men, all of them married... -The heat and fury of the jungle tears the veneer of civilization from these women.

-...something 1950s society and the fee-paying public could not tolerate.

-I think Grace Kelly just liked sex.

I mean, there's a saying that on "Mogambo," they accused her of sleeping with Clark Gable, who was married at the time.

-Grace Kelly playing a part every woman secretly understands.

-And she just said, "Well, what else were we supposed to do?

We were in the jungle.

It was nobody around."

And I thought, "Yeah, that makes perfect sense."

-In "To Catch a Thief," she is absolutely at her most playful, beautiful, sexy, and high-society.

She was actually seen as a very sexy, flirty, fun-loving beauty.

That sexiness is integral to her image.

It's not surprising that she had an active sex life.

-In Hitchcock's crime thriller "Dial M for Murder," art was starting to imitate life, with Grace playing an unfaithful wife.

-It's a very important film for Grace's image.

It shows that sexuality brought out by Hitchcock.

-You could not take your eyes off her.

-But her love affair with costar Ray Milland almost destroyed her career.

♪♪ -I understand that she thought the marriage was over and that he was going to leave his wife.

But Grace did develop an image as being a bit of a husband stealer, of a homewrecker.

If that reputation had been maintained, then that could have done her quite a lot of damage.

-If MGM had terminated her contract, Grace would have missed out on millions.

-But Milland went back to his wife.

That affair didn't last.

-There was a double standard in Hollywood in the 1950s where male stars like Clark Gable, like Ray Milland, like Bing Crosby, were seen to be doing well if they had an affair with a younger woman, whereas it could ruin her reputation and really do damage to her to be seen to be having affairs with men as a single woman.

-The negative rumors and failed romances were starting to take their toll.

-She didn't enjoy the sort of brutality of the movie business.

She followed her heart, and her heart got broken quite a lot of times.

-As an actress, Grace Kelly was box office gold.

But as a woman, the clock was ticking.

-It's hard to believe, but at 26, 25, 26, Grace was the wrong side of her 20s.

-As she got older, she became more and more anxious about not being married and not having children.

-All this other stuff was a stepping stone to marriage.

Eventually, you got married.

-Just five years into her career, Grace shocked everyone.

♪♪ She had found her prince.

-A big day in Philadelphia, when millionaire John B. Kelly's daughter, film star Grace Kelly, announces her engagement to Prince Rainier, the 32-year-old ruler of the pocket state of Monaco.

-It's hard to know really what was going on in her head.

-Wedding plans plunged her movie career into chaos.

-Well, actually, I have four more years to go on my contract, so what will be done, I don't know.

-Grace probably thought, "I'm marrying a real prince, so it's going to be a fairy tale, right?"

But she didn't have a fairy tale, and she didn't have a fairy-tale ending.

-A princess is not about expressing your desires, about doing what you want.

It's about serving the crown.

-I don't think she realized how much she would miss her career.

-She would see her value skyrocket.

-She's a premium brand, and that really hit a whole new level.

-So why did the decision to join Monaco's royal family cost Grace Kelly millions?

Long before Harry and Meghan, there was another lavish fairytale wedding between an American actress and a European prince.

♪♪ On the 19th of April, 1956, the queen of Hollywood married her real-life prince in a ceremony watched by 30 million people.

-This was a gigantic royal wedding, bigger in a sense than that of Princess Elizabeth, later to be Elizabeth II.

It was bigger than that of Princess Margaret.

The entirety of Hollywood was there, plus royalty, plus aristocracy.

-Wedding gifts have come from all over the world, gifts in gold and silver, jewelry and fine porcelain.

-And then there's the palace, and there's the prince.

All of this is like a movie.

♪♪ -And Grace had the movie-star dress to match the occasion, a gift from MGM made by their Oscar-winning costume designer.

-Grace Kelly's wedding dress was the fairy-tale dress.

-Just elegant, sophisticated, serene.

-Tight-fitted bodice, big, billowing skirt, little Juliet cap, all inset with seed pearls.

-It was iconic, and it's influenced fashion designers even today.

-Probably one of the best known is Sarah Burton, from Alexander McQueen, designed Kate Middleton's wedding dress when she married Prince William.

They looked at Grace Kelly's wedding dress for their inspiration, and when Kate came out wearing this dress, you could instantly see the similarities.

-The wedding is over, and Prince Rainier's bride is no longer Grace Kelly, but Her Serene Highness Princess Grace of Monaco.

-But this fairy-tale wedding also came at a price.

There was a dowry to pay.

-The dowry was we believe to be $2 million, and that's a large amount of money in the 1950s.

It'd be around about $20 million now.

And it is believed to be the case that 1 million of the dollars was Grace's own savings, and the other million was taken from her potential inheritance.

-The proud and independent Grace didn't want to turn to her father to pay the dowry.

-Which is why, to a large degree, it didn't come from her father's money as theoretically it should have done.

It came from Grace's money.

-In paying for her own dowry, Grace put a significant dent in her hard-earned personal fortune from acting and modeling.

But as a princess, Grace Kelly now had access to wealth on a scale barely imaginable, even in Hollywood.

She dined in the best restaurants and holidayed in the exclusive resorts of Verbier and St. Moritz.

-Twice a day every day, Prince Rainier personally feeds his pet seal.

On this day, it was very much a family occasion, just like any other family at the zoo, except that they own the zoo.

From a vantage point in the palace, the prince and his children survey what is theirs.

[ Announcer speaking indistinctly ] -The Grimaldi royal family owned, among other things, a 12th-century palace with 200 rooms, a $6 million fleet of yachts, more than 100 vintage cars, a stake in the Monte Carlo casino, and a chateau in Laon, northern France, with an estate six times bigger than the state of Monaco.

-Grace probably thought, "I'm marrying a real prince, so it's going to be a fairy tale, right?"

-And open Rolls-Royce waits to drive them on a tour through the streets of Monte Carlo.

-But adjusting to her new role wasn't easy.

Just like Meghan Markle and Kate Middleton, stepping into royal shoes meant taking on a very different role and genuinely acting the part.

-Grace had enjoyed a huge amount of freedom as a movie star.

She lived independently.

She'd done what she wanted.

She'd had friends.

She'd had boyfriends.

A princess is not about expressing your desires, about doing what you want.

It's about serving the royal family.

And it's really very much about suppressing your own desires.

-Grace Kelly seemed trapped in a gilded cage.

-To suddenly live this life that is really very restricted is a huge change, and I think it was very difficult for her.

-Miss Kelly, will you continue with your career?

-Well, that decision will be made by the prince.

-Has it already been discussed, may I ask?

-Oh, yes.

-It had been decided that Grace's role now was to be a wife, mother, and ribbon cutter.

-Prince Rainier was clear that he didn't want her to work, whether or not she thought she was going to bring him round or whether she would go back to work after she'd had children.

But it was clear that she did want to go back to work.

-Five years and two children into her marriage, Grace's dreams of a Hollywood comeback were dashed forever.

The Monaco establishment stopped her taking the starring role in Alfred Hitchcock's "Marnie."

-I think it was really frustrating for her, having worked so much, to be -- to be told she couldn't work at all.

-Hitchcock was furious.

Her marriage to Rainier ended her career.

That was the end.

She couldn't do it.

-She was quite isolated, and I think she lacked that kind of outlet for her creativity that was a lifelong need in her from when she was a girl.

-I think I was on my way to becoming a good actress.

I felt as though I was just beginning to -- to glimpse into what it was all about when I stopped.

-I think it was an enormous sacrifice that she made and a sacrifice that she made unknowingly.

I think she expected to go back to work and regretted for the rest of her life that she gave up her career.

-There would be no going back to Hollywood.

Grace couldn't have it all.

She had committed herself to Monaco.

But looking forward to the time she could retreat from the circus of royal life, she bought her grandfather's humble cottage in County Mayo, Ireland.

-Doris Day, star of the new film, arrives at the Screen Directors Guild Theater.

-Meanwhile, back in Hollywood, Grace Kelly's contemporaries continued making movies, winning Oscars, and earning millions, millions that Grace Kelly was to now miss out on.

Audrey Hepburn was born the same year as Grace Kelly, also into a wealthy family.

Like Grace, she was a model, stage actress, and then movie star.

But Audrey Hepburn's remarkable career lasted 40 years, eight times longer than Grace Kelly's.

So how many millions was Audrey Hepburn raking in?

-By the time that she was well-established in Hollywood, she could command huge fees on a regular basis.

In the 1960s, she earned $1 million for half a day's work shooting some adverts.

Today, Audrey Hepburn's net wealth is estimated at $100 million.

-Grace Kelly's peer Doris Day was born into a middle-class family in Cincinnati.

Her acting career spanned 20 years and culminated in her own TV show.

Doris Day's net worth is an estimated $200 million.

-So by quitting Hollywood early, Grace Kelly missed out on a long and lucrative career that could have been worth up to nine figures.

♪♪ -Shut out of Hollywood, Grace Kelly's earning power had never been lower, but her value had never been higher, especially to Monaco and the Grimaldi royal family.

-There's no doubt that Prince Rainier was attracted to her, at least in part because she would bring all of this glamour and prestige to Monaco.

-And she did.

-This place that had been ignored by most of Europe, that many people in America didn't even know where it even was, suddenly became the most glamorous place you could possibly imagine.

Everyone wanted to go there, and they wanted to go there to do two things -- to gamble, and they wanted to increasingly buy property.

And really thanks to Grace, Monaco becomes this powerhouse of money.

-Today, Monaco is home to more than 12,000 millionaires, the highest concentration on earth for one reason -- none of them pays any tax.

-Since 1869, Monaco residents haven't been charged any personal income tax.

Prince Rainier and Grace even saw off a challenge by neighboring France in the 1960s to impose direct taxation.

Today, for those in the highest tax bracket, for every £100 earned, they save £45 of tax, so it's no wonder that so many of the super-wealthy exile themselves in Monaco.

-People like clothing tycoon Sir Philip Green, worth $2.4 billion and avoiding close to a billion in tax, easyJet founder Stelios worth $1.3 billion, and Formula One champion Lewis Hamilton, worth $285 million.

Today, the Monaco economy is worth more than $7.8 billion.

That's almost $200,000 per resident.

-Fashionable Avenue Montaigne sets a new style with the arrival of Princess Grace of Monaco, greeted by Dior designer Marc Bohan.

-Grace Kelly turned Monaco into a millionaires' playground but was also proving herself a regal cash cow for designer brands, especially ones that sparkled.

-She was introduced to jewelry by Hitchcock, who took her on a window shopping spree by all accounts and introduced her to the window of Cartier.

The prince presented her with a ruby and sapphire eternity-style engagement ring.

Grace Kelly's second engagement ring was the emerald-cut diamond, very simply set in a platinum mount with two smaller baguette-cut diamonds, one to each side.

Another iconic piece of jewelry that Grace Kelly owned were the Alhambra necklaces first created by Van Cleef & Arpels in 1968, all beautifully set with gold beadwork and gold chains in between.

-Grace Kelly's jewelry collection would have been worth tens of millions of dollars in today's money.

-The fact that she would be seen wearing their creations endorsed their product for them and took them to a higher plane.

-Cartier and Van Cleef & Arpels both became royal suppliers, with Cartier valued at $12 billion today, and Van Cleef & Arpels worth $32 billion -- more money that Grace had generated for others and missed out on for herself.

♪♪ And beneath the glamorous, polished veneer was a sadness.

She'd lost her career.

She was juggling young children and royal duties, and her own family were at arm's length.

Then in June 1960, Grace's father, Jack, died.

♪♪ -Grace Kelly really tried to please her father.

He just rebuffed her.

He rebuffed her his entire life.

Even after she'd become a big movie star, she married a prince, everything, it wasn't good enough.

-But would Grace's father finally reach out and leave her a financial windfall on his death?

-In 1960, when he died, Jack's estate was valued at just over a million dollars, which would be the equivalent to nearly $11.5 million today.

He bequeathed all his personal property -- so that's clothing, sports equipment, trophies and jewelry -- to his son, Grace's brother, Kell.

All the furniture and his two houses, one in Philadelphia and one in Ocean City, went to Grace's mother, who also received 1/3 of his estate, and the remaining 2/3 were to be divided equally amongst his children.

So if we calculate how much Grace could have inherited, it would have been 1/4 of 2/3 of the value of her father's estate, so around about $190,000, which in today's money would have been the equivalent of $1.7 million.

-Money that she had effectively already surrendered as her dowry for marrying a prince and the final blow from a father she could never impress.

♪♪ After his death, Grace threw herself into royal service, despite what seemed to be an increasingly loveless marriage.

-I think there was a sense of frustration and some despondency about there being nothing left.

-But nobody predicted the shocking events to come.

-It was so sudden.

-An innocent drive along Monaco's famous hairpin bends would turn to tragedy.

-It made you think about the finiteness of life.

Your life could be over just like that.

-There was so much more she could have done.

-Millions would be lost and made when the world was robbed of a global icon.

-The tragedy is that she was lost so early.

-The news of Grace Kelly's death really shocked everyone.

She was too young to die, and it was a worldwide tragedy.

-On September the 13th, 1982, tragedy struck.

♪♪ Driving with her daughter Stephanie through the steep, winding roads above Monaco, Grace suffered a fatal stroke.

♪♪ Her car crashed through a parapet wall and plunged into a ravine.

♪♪ She was just 52 years old.

-The news of Grace Kelly's death really shocked everyone.

She was too young to die, and it was a worldwide tragedy.

♪♪ -Incredibly, even though she died unexpectedly, her will in America left only a fraction of her expected wealth to a trust fund.

So where had all the money gone?

In the hunt for the missing millions, financial investigator Gemma Godfrey has found a second will, an Irish one, with details of the cottage Grace bought in Drumilra, County Mayo.

-It says that she bequeathed this property equally to each of her children, and her will also says that in 1982, the value of the property was £18,000.

So today, if you take into account the rise in property prices, that'd be worth $350,000.

♪♪ -The house itself was worth comparatively little but, as her grandfather's home, had huge sentimental value for Grace.

Today, the house has gone to rack and ruin but still belongs to the Grimaldis.

Grace Kelly's own family home, the Philadelphia mansion built by her father, was bought by her son, Prince Albert, who restored it to its 1950s splendor.

That, too, is owned by the Monaco royal family, valued at over $1 million.

♪♪ But all this can still only represent a small slice of Grace Kelly's wealth.

♪♪ Shrouded in secrecy and locked away in the personal archives of the Grimaldi royal family is a mysterious third will.

-We've asked to see a copy, but the palace said that it's not publicly available.

They told us that Prince Albert and his family don't wish to disclose its contents.

-But Gemma has unearthed details about the wealth of the current royal family.

-Today, Grace Kelly's son, Prince Albert of Monaco, owns shares in the company that owns four Monte Carlo casinos and five luxury hotels, and he has personal assets that have been valued around $1 billion.

And Grace Kelly's daughter-in-law and her successor as Princess of Monaco, Charlene Wittstock, is today estimated to be worth $150 million.

-Grace Kelly's remarkable career spanned more than three decades, from a jobbing model and stage actress to the dizzy heights of Hollywood, designer muse, and royal princess.

So what should the fortune of this global superstar have been worth today?

From the meager American will, rundown Irish cottage, and Kelly family inheritance, her hard-won earnings as a savvy model and actress, and the stunning clothes and jewels gifted across her lifetime... -Grace Kelly is worth over $57.5 million in today's money.

♪♪ -Add in the untold wealth she amassed as a royal, and just where are these missing millions?

It was likely all bequeathed to her children, to the Monaco royal palace, and to her charity.

♪♪ Grace Kelly set up her charity, The Princess Grace Foundation, in 1964 to support the families of sick children and help young artists in America.

-What Grace did was very much ahead of the curve, very progressive.

She becomes CEO of her own charity, and she raised huge amounts of money.

-Years after her death, she continues to generate millions for charity, giving away more than $16 million in recent years, money made through licensing the Grace Kelly name and image for luxury brands.

-Because Grace Kelly won an Oscar and she went on to marry a prince, she's got a real premium brand.

So a lot of people that want to add value to their product are going to choose someone like Grace Kelly.

People like the Ritz Hotel have got a Grace Kelly Suite.

Montblanc pens have got their own Grace Kelly pen, even down to QVC do their own line of jewelry.

Some people estimate Grace Kelly's value today to be worth around $100 million.

-Proof indeed that Grace Kelly's iconic image remains immensely lucrative for the brands, her children, and her charity.

-She had a really clear sense of what her priorities were.

-She knew the value of money.

-And had she lived longer and made different choices, her fame and fortune would have been even greater.

-Grace Kelly was, of course, a hugely successful movie actress.

However, what's clear to me now is she was also a fantastically successful businesswoman.

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