Actresses Dakota and Elle Fanning are reportedly distant cousins of Britain's Kate Middleton.
Researchers at Ancestry.com have found that the sisters, who were born in Georgia and have starred in a number of major films, may share blood with British royalty after looking through seven centuries of family trees.
The ancestry site claims the siblings are descendants of King Edward III, who ruled England for nearly 50 years from 1330 to 1376, through their mother Heather Joy (née Arrington), who is a retired professional tennis player.
Elle, 16, who plays Princess Aurora in Disney's 'Maleficent' and Dakota, 20, would therefore rank as 22nd great-grandchildren of King Edward III.
Michelle Ercanbrack, a family historian for the site, told People.com: "Generation after generation, the lines we looked at pieced back directly to King Edward III proving that Elle is a direct descendant of royalty. You can consider her a long-lost princess. This connection is so unique and rare."
If the researchers are correct it would mean King Edward I, also known as Longshanks, who is the grandfather of King Edward III, is an ancestral link between Kate Middleton and the Fannings.
The Duchess of Cambridge's mother, Carole Middleton, is also a granddaughter of King Edward III, which gives the stars another link to the family.

An Australian newspaper has decided to publish the controversial photograph of Britain's Duchess Catherine baring her bottom.
The Sydney Daily Telegraph ran the snap of Catherine showing off her bum after her skirt was blown up by the wind from a helicopter and claims it would be "ridiculous" to follow suit with Britain's media, who decided not to use the photograph.
A piece has been published in the newspaper, stating: "Why should the media stick to an antiquated code of etiquette when Kate doesn't bother to protect her own modesty?"
In the piece, writer Annette Sharp goes on to say: "Why would the cheeky French, German and American media, with no Commonwealth ties to Britain, be expected to honour such an antiquated code of etiquette? Why should the media be responsible for turning a blind eye when the royals aren't always vigilant about keeping themselves nice?"
Their decision to run the picture comes after German newspaper Bild used the image on their website, taken by celebrated photographer Diane Von Furstenberg, during Kate Middleton and Prince William's recent trip to Australia on a visit to the Blue Mountains near Sydney.
The feature states: "Photos show our favourite Duchess Kate, 32, in the Australian Blue Mountains. The rotor blades of the royal helicopter swirl the air so that Kate's summer dress blew up - giving a clear view of her beautiful bum!', the headline also reads: "Clothes ban for Kate?"
The image is situated next to images of Kim Kardashian and sister Khloe showing off their curves.

'Big Brother' producers have forced this year's contestants to undergo IQ tests.
Show bosses reportedly wanted "very, very clever" housemates who will be able to cope with the gruelling mind games and head-to-head contests they are planning for this year's 'Big Brother: Power Trip' series and are confident they have set the scene for an explosive programme.
Rylan Clark, who fronts spin-off show 'Bit On the Side', said: [The contestants are] ruthless, sly and vindictive.
"This year they're very, very clever and they've all been IQ tested.
"They are the type of people who will do anything to get what they want.
"It'll be a fight to the finish."
Rylan also teased that technology will be allowed in the house for the first time ever, suggesting "heavily monitored" use of websites such as Facebook and Twitter will be permitted as part of the games.
He told the Daily Star newspaper: "Technology will be ­allowed in the house for the first time ever this year.
"There might be some element of social networking, which will obviously come into play with the power-struggle element.
"It'll all be heavily monitored, though."
'Big Brother: Power Trip' begins on June 5 at 9pm on Channel 5.

David Walliams has written a book about Simon Cowell and his son Eric.
The 'Britain's Got Talent' judge has given the media mogul - who welcomed his first child with New York socialite Lauren Silverman in February - 50 copies of the book, titled 'David Walliams Presents Baby Eric'.
Simon, 54, was surprised by the gesture and initially believed it was going to go on sale in shops.
An insider told The Sun newspaper: "He [Simon] didn't quite know what to say."
Simon later said: "It is very sweet."
David shared a picture of the book's cover, which depicts Simon holding the baby while his girlfriend Lauren is beside them beaming with pride.
He captioned the picture, posted on his Twitter account, by writing: "This is the cover of the book I wrote especially for @SimonCowell & Lauren's son Eric... (sic)"
A blurb on the back cover reportedly reads: "Simon Cowell was the man who thought he had everything, until the day Baby Eric arrived in his life."
David - who has 12-month-old son Alfred with wife Lara Stone - has written a number of children's books.
He first signed a contract with HarperCollins in 2008 and made his debut with 'The Boy in the Dress', illustrated by Quentin Blake, while his most recent book is titled 'Demon Dentist'.

Mel B will have to prove she is devoted to 'The X Factor' before she is named a judge.
The Spice Girls star has reportedly been asked to prove she will be able to dedicate enough time to the job on the ITV talent show before Simon Cowell makes the official announcement that she will complete the line-up of judges, which includes himself, Cheryl Cole and Louis Walsh.
A source said: "For Mel to get the job she has to prove she can devote enough time to the show and prove her other commitments won't get in the way."
The 38-year-old star is currently on the judging panel of 'America's Got Talent' and 'The Voice Kids' in Australia, and although Simon wants to make the final announcement next week, he won't do so until he has been assured she will put her all into mentoring her acts.
The source told The Sun newspaper: "She is the front-runner for the fourth judging spot but will only get it if Simon is satisfied it will work."
Cheryl and Simon confirmed earlier this year that they would be returning to the show after a four-year hiatus and the media mogul is said to be keen to hire Mel for the final seat as her boisterous personality will likely see her clash with her fellow judges,
The source added: "'The X Factor' judging panel is all about the drama and Mel is sure to rub Cheryl up the wrong way, which Simon is really looking forward to."

Charlie Cox has been cast as Daredevil in a new Marvel TV series. The British actor - best known for his role as Owen Slater in 'Boardwalk Empire' - will play the blind superhero in the Netflix show, reports Variety. The 31-year-old star has beat sti...

Emma Barton has returned to 'EastEnders'.
The actress made a surprise return to the BBC One soap in last night's (27.05.14) episode as Billy Mitchell's estranged wife, Honey Mitchell, who was last screen on screens in 2008.
Honey was seen back in Albert Square with her and Billy's two children, Janet and William.
Following the episode, executive producer Dominic Treadwell-Collins teased on Twitter: "We will keep the surprises coming... #EastEnders (sic)"
Emma also tweeted about her comeback, writing: "Thank you so much for all of the lovely messages.. Haven't seen ep yet.. But very excited to be back on Britain's Best Sq! (sic)"
The actress first appeared in Walford from 2005 to 2008 and was at the centre of an emotional storyline when Billy (Perry Fenwick) and Honey's daughter Janet was born with Down's syndrome.
Honey's return follows Jane Beale's surprise reappearance in Albert Square in January, as well as brief stints from past characters Libby Fox (Belinda Owusu) and Christian Clarke (John Partridge).
Elsewhere in last night's episode, viewers were dealt another shock as soap favourite David Wicks (Michael French) suffered a heart attack just before his wedding to Carol Jackson (Lindsey Coulson).

Simon Cowell and Lauren Silverman are renting a Hamptons house.
The happy couple and their three-month-old son Eric will be making the most of their first summer together by renting an exclusive Bridgehampton property for the holiday season.
The 'X Factor' boss and his girlfriend are also looking at finding a more permanent abode in New York City and were seen searching for the perfect pad on the Upper East Side, near where Lauren's seven-year-old son, Adam, lives with his father, Andrew Silverman.
The New York Post newspaper's Page Six column claims the couple have scrapped plans to find a home in Miami in favour of New York so they can be closer to Lauren's son following the dramatic upheaval of his family life last year, when his mother's affair with Simon was unmasked due to her pregnancy.
Meanwhile, Simon's friend and 'Britain's Got Talent' colleague Amanda Holden thinks the music mogul is going to propose to the socialite in the near future and predicts they will expand their family.
She said: "I do [think they will get married]. And I think they'll have more children too, because he loves it.
"Simon definitely should ask Lauren to marry him. He shouldn't let her get away. Lauren's such a good influence on him."

Deryck Whibley has vowed to be back on stage "soon".
The Sum 41 rocker was recently hospitalised due to the effects of heavy drinking and has thanked fans for their compassion and support as he fights to beat his addiction.
He wrote on his website: "I just wanted to thank you all so much for sending gifts and all of the compassion and support you have shown me.
"It really means a lot to me in this time of recovery. I will be better soon and back out on stage before you know it."
The 34-year-old rocker - who was previously married to Avril Lavigne - admitted earlier this month he had been "scared straight" after suffering some worrying health problems that saw him come close to death.
Alongside pictures of himself looking thin and frail, he wrote: "The reason I got so sick is from all the hard boozing I've been doing over the years. It finally caught up to me.
"I was drinking hard every day. Until one night. I was sitting at home, poured myself another drink around midnight and was about to watch a movie when all of a sudden I didn't feel so good. I then collapsed to the ground unconscious."
Deryck panicked when he woke up in an intensive care unit, but is determined to get his life back on track.
He added: "I had no idea where I was. I was so freaked out. My liver and kidneys collapsed on me. Needless to say it scared me straight. I finally realised I can't drink anymore. If I have one drink the docs say I will die (sic)."

Liv Tyler doesn't think family life can "flourish" if you focus on your career.
The 36-year-old star - who is the daughter of Aerosmith frontman Steven Tyler and raises 10-year-old son Milo with ex-husband Royston Langdon - believes it is impossible to perfectly balance a personal and professional life and one will always suffer at the expense of the other.
She told UK's Red magazine: "Perhaps I shouldn't think this way but, from a very young age, I had this idea in my head...
"That if you are very successful in your career and you're giving all of your attention to that, then your family life will not ... I need to word this in the right way....
"The life of your family possibly won't flourish as it might. But when you focus on your family and you put that first, then your career suffers in some sort of way.
"I can live with the career part not going so well, I think, but I don't think I could live with my family not."
Liv admires her A-List pals, designer Stella McCartney and actress Gwyneth Paltrow - who has kids Apple, nine, and Moses, eight, with estranged husband Chris Martin - for the way they have managed to strike a healthy balance between work and motherhood.
She added: "I see Stella [McCartney] whenever she's here, and we have a weird, crazy conversation, say 'I love you' and then she's jetting off back to London.
"She's got four kids, and a million businesses. And Gwyneth's just really good at everything. She's very organised, whereas I'm far more sensitive and adaptable.
"She's good at structure and routine and schedules, whereas I get lost all the time. I'm always late and always rushing."

Dean McDermott has Tori Spelling's name tattooed above his penis.
The '90210' actress discussed the intimate inking with a group of friends on last night's (27.05.14) episode of 'True Tori' after one of them suggested her spouse - who admitted to having a one-night stand in Toronto last December - should sign a contract saying he'd never cheat or drink again, and if he did he would get "nothing".
Tori initially joked he should get the document tattooed on him but then admitted body art didn't prevent him cheating before.
She said: "Should I have him do a tattoo on his body? I mean clearly that didn't stop him. You know the tattoo he has, right? Down there it says 'Tori's'.
'"It's above [his penis]. It's above the pubis. It says 'Tori's'. And then months later he cheated on me."
The episode saw the couple repeatedly clash over whether Dean should return to Toronto to shoot a new series of 'Chopped Canada', and though Tori was initially adamant he should put their family first and stay at home, she eventually relented and agreed it would be best for his career to make the trip.
As her left, Dean - who has children Liam, seven, Stella, five, Hattie, two, and Finn, 21 months, with his wife - vowed to be "Mother Theresa" while he was away as he didn't want to jeopardise the progress they have made in repairing their marriage.
He said: "You and the kids are more important than the show...
"I know what's at stake here. But I will not let them down.
'I'm going to be Mother Teresa, I'm going to be so good. These babies are my life."

A sequel to 'My Big Fat Greek Wedding' is in the works.
Nia Vardalos is reprising her role as Toula Portokalos, in the follow-up to 2002's comedy with John Corbett who played her love interest in the original, and feels she's ready to take on the project since she's "experiencing motherhood" after she adopted a daughter, Ilaria, with husband Ian Gomez.
Vardolas wrote on Twitter: "I'm working on the MBFGWedding sequel; now that I'm experiencing motherhood I feel ready to write this next chapter.
"A few jaded press corps will claim I ran out of money or just want to kiss John Corbett again. One of these things is true. (sic)"
Later she added: "Re: #MyBigFatGreekWedding2, thank you for the love, yes the entire big fat family is invited back for the sequel. (sic)"
Vardalos has written the script for the project and the plot involves a "bigger and fatter" wedding than that in the first film, according to The Hollywood Reporter.
Rita Wilson and Tom Hanks will produce with Gary Goetzman, and no director has been cast yet.
'My Big Fat Greek Wedding' generally positive reviews and was a box office success and grossing over $368.7 million worldwide.