Age: 24 Net worth: $280 million Country: UK India Rose James inherited an estimated 40% of her maternal grandfather Paul Raymond's $1 billion empire upon his death in 2008. Raymond's wealth — known as the Soho Estates — came from varied property investments in London's Soho district, establishing Britain's first adult entertainment bar and introducing pornography magazines to the country though Paul Raymond Publications. James is currently focused on Soho Revue Gallery, the young artist-focused contemporary art gallery she opened last spring with her then-boyfriend Will Pelham. The socialite has breakfast at the family-owned Soho House every morning, enjoys traveling, and aspires to follow in her grandfather's footsteps to become an entertainer.Net worth: $2.1 billion Age: 25 Country: US While still a student at Stanford in 2011, Evan Spiegel helped found Snapchat, the messaging app that lets users send disappearing photos to friends, with his classmates-slash-fraternity brothers Reggie Brown and Bobby Murphy. The app took off, making Spiegel a bona fide billionaire by age 23. Today, he continues to run the $16 billion company as CEO. He hasn’t tied the knot yet, but it’s no secret that Spiegel’s been dating supermodel Miranda Kerr. The pair are often photographed out in Los Angeles, and Kerr is all smiles talking about him. He's just a really kind person and very genuine and very authentic and I really appreciate that about him,” she told E!. Age: 32 Net worth: $4.5 billion Country: US Elizabeth Holmes is the youngest female billionaire in the world thanks to the success of her pain-free, needle-free blood testing company Theranos. When she was 19, Holmes dropped out of Stanford to found the company and has dedicated her life to it since. According to a 2014 New Yorker profile, the CEO lives in a two-bedroom condo in Palo Alto...no longer devotes time to novels or friends, doesn’t date, doesn’t own a television, and hasn’t taken a vacation in ten years. Though Holmes' image is that of a well-intentioned hard worker, she's facing harsh criticisms for reports claiming dodgy business practices. This is what happens when you work to change things, Holmes fired back. First they think you're crazy, then they fight you, then you change the world.Net worth: $10.6 billion Age: 30 Country: US An heir to the Walmart fortune, Lukas T. Walton is the grandson of the superstore’s founder Sam Walton. The young Walton is worth nearly $11 billion, but the extent of his wealth only recently came to light, when news broke in November that he had inherited twice as much as his mother, Christy, after his father John died in a plane crash in 2005. Walton’s always stayed out of the public eye and continues to keep a low profile — little is known about the secretive heir, and he’s rarely, if ever, photographed. As a child, Walton was diagnosed with cancer, but survived. He went on to earn a degree in environmentally sustainable business from Colorado College and is now a partner at Cuna del Mar, a private equity firm that invests in aquaculture. Age: 49 Net worth: $2.4 billion Country: Turkey Turkish billionaire Filiz Sahenk helms the luxury brand clothing and tourism businesses of her late father's private conglomerate Dogus Grubu. Sahenk oversees the company's retail partnerships with several global brands including Emporio Armani, Gucci, and Loro Piana. Despite being one the most affluent women in Turkey, Sahenk isn't a public fixture. She's a behind-the-scenes advocate for women's leadership and development and an active philanthropist as president of the Ayhan Sahenk Foundation, which supports education, the environment, and social and healthcare-related causes. She also reportedly has a passion for collecting antique Turkish art.Net worth: $35.8 billion Age: 42 Country: US As a Stanford PhD student in 1998, Sergey Brin partnered with classmate Larry Page to create BackRub, an early search engine. The project eventually morphed into Google — now called Alphabet — one of the largest and farthest-reaching companies in the world, worth a whopping $475 billion. While Page handles the more administrative side of running Alphabet, Brin focuses on developing the company’s next big innovation, exploring “moonshot” projects and ideas. Brin’s personal life has gone less smoothly, however. In 2013, he separated with wife Anne Wojcicki, founder of 23andMe, and shortly after that she learned Brin was having an affair with Amanda Rosenberg, a Google employee who worked on Google Glass. The two divorced in May 2015 after eight years of marriage. Brin and Rosenberg are no longer together, either. Age: 58 Net worth: $4.7 billion Country: Israel Israeli-American Shari Arison is owner of Arison Group, a global investment and philanthropy group venture by her father. The group has major interests in finance, real estate, infrastructure, renewable energy, and water. When Arison's father died in 1999, she inherited about 35% of his wealth. The businesswoman and philanthropist has authored four books on the subjects of good deeds and sustainability and is a major advocate of community service. The thrice-divorced mother of four has residences in Tel Aviv, Israel, and Bal Harbour, Florida.Net worth: $21.4 billion Age: 51 Country: Germany Georg Schaeffler served in the German military and held a short career in corporate law in the US before jumping aboard his father's company, Schaeffler Group, the nearly $11 billion in sales ball bearings and auto-parts maker that Schaeffler now co-owns with his mother. Schaeffler has four sons with his ex-wife, Bernadette Muehelm, but the couple have been divorced since around 2007. Schaeffler also previously had an on-again-off-again relationship with Erika Nazem, the owner of a Dallas gym. He and Nazem were reportedly registered to marry in 2013, but the relationship reportedly ended.Age: 66 Net worth: $34.3 billion Country: US Though she's one of four heirs to the Walmart fortune — and the 15th richest person on earth — Alice Walton never took an active role in the mega-retailer's daily operations. Instead, she's become a patron of the arts with a personal collection that includes pieces from Andy Warhol, Norman Rockwell, and Georgia O'Keefe. In 2011, the heiress opened the Crystal Bridges Museum in Arkansas, where a number of her famous paintings are on display. Walton is active in her family's philanthropic endeavors and recently donated 3.7 million of her Walmart shares — worth about $225 million at the time — to the Walton Family Foundation. The divorced billionaire's personal real estate portfolio includes a 6,346-square-foot New York City condo and a recently listed pair of $48 million Texas ranch properties where she raised and rode horses.Net worth: $19.9 billion Age: 60 Country: Saudi Arabia Prince Alwaleed built his fortune with savvy investments in a range of companies across the US and the Middle East. He founded Kingdom Holding Co. in 1980 and has since invested in everything from real estate to entertainment to education, with stakes in companies like Twitter, The Four Seasons, Time Warner, and Motorola. The prince has been divorced four times, most recently parting ways with Princess Ameerah Al-Taweel in 2013. The pair remain on good terms, however — a position he strives to maintain with all of his exes. “I had three unsuccessful marriages, yet I have a very good relationship with these wives,” he told Vanity Fair prior to his split with Ameerah.