PUBLISHED: 19:23 EST, 26 May 2012 | UPDATED: 09:24 EST, 27 May 2012
When Priscilla Chan married her long-time boyfriend, Facebook founder Mark Zuckerberg, last weekend she looked every inch the fairytale bride.
In a stunning full-length white gown, 27-year-old Priscilla smiled serenely as she exchanged vows with Zuckerberg, 28, worth an astonishing £12 billion, in a surprise ceremony.
Her transformation into the wife of the world's youngest billionaire, however, is more remarkable than it may seem.
For Priscilla is the child of a Chinese-Vietnamese father who arrived in America with his family in the Seventies after spending time in a refugee camp.
Billionaire bride: Facebook founder Mark Zuckerberg wed Priscilla Chan last weekend in California
Later Dennis Chan, 47, raised enough money to open a Chinese restaurant, where he worked gruelling 18-hour days as he dreamt of his first-born daughter living the American dream.
Priscilla was raised largely by her grandmother as her mother Yvonne also worked long hours at the Taste of Asia in Boston. At the 1,200-pupil state-run Quincy High School in the working-class town of Quincy, near Boston, it quickly became clear that Priscilla was bright - and determined to get on.
Peter Swanson, 66, her science teacher and tennis coach, said: 'She came up to me during that first year, when she was 13, and said, 'What do I have to do to get into Harvard University?''
'I was stunned. In all my years of teaching I have never had a 13-year-old ask a question like that. She knew what she wanted, even back then. I encouraged her to join the tennis team because I knew that Harvard would require her to have a well-rounded resumé.'
He added: 'She was mostly raised by her Chinese grandmother, who spoke no English. She was a very dignified woman who clearly was a huge influence in Priscilla's life. The grandmother was her emotional support. Her parents were working long hours - 18-hour days - at the restaurant.
'Priscilla worked incredibly hard at her studies and graduated top of her class. She gave me a voucher for a free meal at her family's restaurant as a gift.
'It was clear the family came from humble beginnings but were prepared to work around the clock to make something of their new life in America.
'Priscilla had that drive within her. She did everything she needed to round out her resumé and make it attractive to Harvard. And she joined the tennis club – she was not a natural athlete but with hard practice she steadily improved. When she got into Harvard she ran up to me grinning from ear to ear and said, 'See, I told you I would get to Harvard!''
Changing fortunes: The Chans' old restaurant Taste of Asia in Boston - now called Pho & I
Mr Swanson visited Priscilla and her new husband at their £3.5 million home in Palo Alto, California, last year. 'Mark was at the kitchen table working on his computer,' he said. 'Priscilla introduced us and he grinned and said, 'Behind every great man there is a great woman.''
'People are saying how lucky she is to marry him, but he knows he's the lucky one. Priscilla is the ultimate story of the American dream made good. Her parents came to the States with virtually nothing and she has married a self-made billionaire. It doesn't get much better than that.'
Priscilla has closely guarded her family's humble roots, releasing only a few titbits through Facebook's PR machine. Her 'official' biography states that after Quincy High, she studied biology at Harvard where she met Zuckerberg as they queued for the toilet at a party in 2003.
She has recalled: 'He was this nerdy guy who was just a little bit out there.' While Zuckerberg dropped out of Harvard after founding Facebook in his dorm room and moved to California to build his company, she remained at the prestigious Ivy League university. After Harvard, Priscilla attended medical school and graduated as a pediatrician a week before her wedding.
Her family's home is a four-bedroom red-brick detached house in a quiet cul-de-sac in the middle-class Boston suburb of Braintree. But the precise details of how the family arrived in America are unclear.
Determined pupil: Priscilla's yearbook photo from state-run Quincy High School, near Boston
Reports in China say they came originally from the city of Xuzhou in eastern Chandong province, also the home city of Rupert Murdoch's wife Wendi Deng. Others say that the family lived in Nanjing, an industrial town 150 miles west of Shanghai, before leaving to live first in Hong Kong and later in the US.
A source at the Asian-American Civic Association in Boston said it was 'highly likely' the family spent time in a refugee camp, either in Hong Kong or on arrival in the US.
Priscilla's father said he was a refugee who had lived in Vietnam, according to Thai-born Napat Sriwannavit, who bought the 87-seat Taste of Asia restaurant from him in 2006 and turned it into a noodle bar called Pho & I.
Mr Sriwannavit said: 'Mr Chan was a very good man, very good manners. He said he had been a refugee and had lived in Vietnam. He was Chinese but he told me he lived in Vietnam.'
When Priscilla's father sold up, he told the new owner: 'I'm tired of working such long hours.'
Records show Dennis, who now owns a small wholesale fish business, was given a social security number as an 'Asian Refugee' between April 1975 and November 1979.
It is believed that he and his accountant wife, now 50, moved to Massachusetts in the early Eighties. Priscilla and her younger sisters, Elaine and Michelle, were born in the US.
Priscilla has already introduced Zuckerberg to her Asian roots. The couple travelled to Vietnam last December and to China in March.
Of the future, Mr Swanson said: 'Priscilla wants to contribute to society. She was the one who encouraged Mark to start a feature on Facebook encouraging people to be organ donors.
'She knows who she is and what she wants. She and Mark both want to change the world. And they are in the fortunate position of having the resources to do that.'