Roman Abramovich, Russia

Net worth: $18.7 billion

Age: 40

Orphan by age four; grew up with uncle and grandmother. After military stint, dropped out of college to take part in controversial Russian oil-export deals. In 1995, teamed up with fellow Russian Boris Berezovsky to take over oil giant Sibneft for a reported $100 million; sold it to Russia’s Gazprom for $13 billion a decade later. Passionate soccer fan owns U.K.’s Chelsea club; has many other toys, including jets, yachts and a home that reportedly cost $100 million. Recently made headlines for divorce from his second wife and speculation over how much of his fortune she’d get.