The ultimate rags-to-riches billionaires like Oprah Winfrey and Roman Abramovich started with literally nothing. But other more fortunate self-made members of the billionaire club had a little help along the way. We reveal nine of the world's richest people who were bankrolled, at least initially, by their family.

The world's most popular social network may never have got off the ground if the bank of mum and dad hadn't been open for business. Cash was thin on the ground during the early days of Facebook, and the site's founders ended up having to turn to their parents for help.

Eduardo Saverin worked with fellow Harvard undergraduate Mark Zuckerberg, among others, to launch Thefacebook.com back in February 2004. The Brazilian-born entrepreneur stumped up the much-needed money for server space, which no doubt came courtesy of his wealthy parents.

The investment, which totalled around $15,000 (£11.2k), was instrumental in ensuring the early success of the social network. Without this initial cash injection, it's unlikely the site would have taken off in such a huge way.

Saverin wasn't the only Facebook founder who used his parents' cash to bankroll the business. In 2004, the social media giant's current chairman and CEO called on his father Edward Zuckerberg for financial assistance.

Desperate to expand the site and fund its increasingly expensive maintenance, the Facebook co-founder persuaded his father, an affluent dentist, to lend him $100,000 (£75k). Edward Zuckerberg willingly obliged and the rest is history.

In exchange for providing the loan, Edward Zuckerberg was issued with two million shares in the social network giant, which are now worth around $365 million (£272m) – a sensational return on the investment.

In 1994, Jeff Bezos quit his Wall Street job and decamped to Seattle to jump on the internet bandwagon and start his own online retail store. Bezos made a decision to sell books and set about pitching for funding.

The idea of an online bookstore was fairly radical back in the mid-1990s and most potential investors declined to put their cash in Bezos' newfangled enterprise. Except his parents, Mike and Jackie.

The couple loaned their son $300,000 (£224k) – their entire retirement savings – to start the business, and bagged 6% of the company in the process. Their crucial investment, which effectively launched the Amazon site, is worth billions today.

Michael Dell was never spoiled by his parents. The computer billionaire got his first job washing dishes at the age of 12 and wasn't over-indulged with gifts or pocket money. But when it came to establishing his first business in 1984, Dell asked his parents, Alexander and Lorraine, for help.

The first-year college student had created a casual business selling PC upgrade kits to students, and needed capital to register his company and establish it as a proper enterprise. Dell's parents didn't disappoint and supplied the required $1,000 (£745) to get the firm up and running.

Dell's PC's Limited business was a major success from the get-go. The money provided by his parents allowed him to begin selling the upgrade kits to the general public, and Dell was soon turning over millions of dollars a year.

Nike co-founder Phil Knight has his parents to thank for helping him launch what has turned out be the world's number one sportswear company. For starters, Knight's parents paid for the round-the-world trip he embarked on in 1962.

During a stay in Japan, Knight discovered the Onitsuka Tiger brand of running shoes, and managed to secure the rights to act as sole US distributor. This led to the formation of Blue Ribbon Sports, the precursor to Nike.

Knight co-established the firm in 1964 with $50 he borrowed from his father, Bill. Without this cash and the parental support he received, Knight wouldn't have been able to fund his business in the early days, and may never have fulfilled his entrepreneurial ambitions.

Believe it or not, IKEA owes its existence to a small gift of cash from the founder's father. In 1943, 17-year-old Ingvar Kamprad overcame his dyslexia and excelled in his school leaving exams, surpassing his parents' expectations.

Ingvar's father Frans Feodor was so delighted with his son's academic achievement, he rewarded him with a small sum of money. Kamprad used this cash to set up his first company, IKEA, which stands for Ingvar Kamprad [from] Elmtaryd, Agunnaryd, which is the place he grew up.

Kamprad, who started out selling replicas of his uncle Ernst's kitchen table, went on to oversee the ready-to-assemble furniture firm's huge international expansion. Kamprad's frugal parents likely inspired his famed thrifty ways too, which are said to border on miserly at times.

In September 2007, Airbnb co-founder Joe Gebbia and his roommate Brian Chesky came up with the idea of turning their San Francisco apartment into an impromptu bed and breakfast to help pay their rent, which they were struggling to afford.

The roomies realised there was a gap in the market for members of the public to rent out rooms or whole apartments on an ad-hoc basis, so they teamed up with close friend Nathan Blecharczyk in February 2008 to create AirBed & Breakfast.

Low on cash, the trio pooled as much money into the venture as possible, using their savings and maxing out their credit cards to fund the firm. Money borrowed from their parents tipped the balance, and the AirBed & Breakfast site was launched in September 2008.

While many billionaires have relied on their parents to get them out of a sticky financial situation or stump up the all-important cash to get their business started, Alibaba's Jack Ma turned to his sister.

In April 1995, Ma created his first internet business, China Yellow Pages, with a combination of his own money and a loan provided by his younger sister, who was eager to see her older brother get ahead.

The business, which built websites for clients in China, was soon flourishing and helped provide the capital for Ma to create online retail colossus Alibaba in 1999, which he founded with a group of 18 friends in his Hangzhou apartment.

Likewise, Africa's richest person, Aliko Dangote, got his big financial break from a close family member. The Nigerian entrepreneur comes from a long line of entrepreneurs, and had a knack for making money from an early age.

Impressed by his business acumen and go-getting attitude, Dangote's uncle loaned his nephew $3,000 (£2.2k) back in 1977 to help establish the Dangote Group. The company started out importing agricultural commodities.

The kickstart he needed to get the ball rolling, Dangote's first major business venture was a resounding success and the 21-year-old future billionaire was able to pay his uncle back in just three months.