John Fredriksen

Fredriksen's empire includes oil tankers, dry bulkers, LNG carriers and deepwater drilling rigs.

He first got into oil trading in the 1960s in Beirut, bought his first tankers in the 1970s, and ran crude for Iran in the 1980s.

His offshore drilling rig firm Seadrill emerged from bankruptcy in 2018, with Fredriksen helping to raise about $1 billion in new debt and equity.

His biggest holding is Marine Harvest, now named Mowi, which has rolled up competitors to become the biggest fish farmer in the world.

Though set to hand control to twins Kathrine and Cecilie, he has said "My daughters should not have to live with the work everyday I've had."