Is there a secret to becoming that most desirable of beings, a billionaire? Not really. For the most part, it appears to be a combination of personal initiative, natural smarts, and a little luck. All of which is what helped John D. Rockefeller become the very first recorded billionaire in 1916.

Rockefeller, born in 1839, left school at 16 to enroll in a business college, later going to work as an accountant for a company of commission merchants. By the age of 20, using savings and borrowed money, he opened his own commission firm in partnership with Maurice Clark.

But that was only the beginning. Always having an eye open for opportunity, Rockefeller stepped in, at the tender age of 24, to the new and exciting oil boom that began in 1863 in Pennsylvania. His original partnership had swelled to five members, and soon disagreements would drive in a wedge that caused them to sell their refinery, with Rockefeller forming a second company that became Standard Oil.

While his focus remained on the oil business, Rockefeller had other interests, and also involved himself in philanthropy, as do many of today's billionaires, including Oprah Winfrey, J.K. Rowling and Bill Gates. The number of billionaires has grown with inflation, and now covers a variety of fields, with the majority being found in retail, technology and investing concerns.

What's next? The first trillionaire, with bets lying heavily that Bill Gates will reach that unthinkable plateau in the next 20 years.