1. Roman and Irina AbramovichRussian oil billionaire Roman Abramovich was a struggling businessman when he married Irina, his second wife, in 1991. His entire wealth was built up during the marriage.
Russian courts often award a wife half of the wealth built up during—not prior to—the marriage, which in Abramovich's case was his whole fortune, though Irina settled for less in their 2007 split: $300 million, which may sound like a lot, but that was only 1.6% of his $18.7 billion fortune at the time. Today, Abramovich is worth $10.2 billion.