Net worth: $4.7 billion
Forbes rank: 295
Background: Frère’s father was a nail merchant, and when he passed away, Frère left school at 17 to run the company. By 30, he began investments in Belgian steel factories, eventually expanding into finance. Today, he owns all of the media, utilities, and oil giant Compagnie Nationale a Portefeuille (CNP), which Frère built from his family’s original business.