Robert Smith: $2.5 billion
When Robert Smith, 54, left Goldman Sachs in 2000 to start his own private equity firm, Vista Equity Partners, his co-workers thought he was crazy. But since then, his success and wealth have skyrocketed, landing him on theÂ
Forbes Billionaire list for the first time in 2016. In 2015, Smith wed Hope Dworaczyk, a former Playboy playmate and mother of his young son in an incredible villa on the Amalfi Coast in Italy.
Oprah Winfrey: $3 billion
Oprah Winfrey, 63, is the only African-American woman to make the Forbes billionaire list. She overcame a tough childhood to become the well-known and beloved media mogul she is today. While generous with her wealth, Winfrey still maintains an enviable lifestyle. Earlier this year, Winfrey delivered the commencement address at Smith College, telling graduates the secret to success is serving others.
Isabel Dos Santos: $3.1 billion
Isabel Dos Santos and Sindika Dokolo.
The wealthiest of the three woman to make this list, and the youngest black billionaire in the world, 44-year-old Isabel Dos Santos is the daughter of Jose Eduardo dos Santos, who has been president of Angola since 1979. Her fortune comes from multiple investments, many of which are controversial and linked to her father, according to Forbes, although Dos Santos maintains her investments are private and independent.
Mike Adenuga: $6.1 billion
Nigerian Mike Adenuga, 64, is chairman of telecommunications company Globacom, which has 36 million subscribers, as well as the majority owner of Lagos-based oil company Conoil, according to Bloomberg. While earning an MBA from Pace University in New York, he drove a taxi to pay the bills. Today, Adenuga, who has seven children, is the second-wealthiest man in Nigeria, according to Forbes.