Net worth: $43 billion

Age: 90

Country: Sweden

Industry: Retail

Source of wealth: Self-made; IKEA

At 17, Ingvar Kamprad founded IKEA, now the world's largest furniture retailer with revenue of nearly EUR 34.2 billion ($36 billion). Kamprad's plan from the beginning was to set up "eternal life" for IKEA, which meant keeping it off the stock market and securing it within a complex corporate structure that includes a charitable arm and a retail and franchise arm, collectively known as Stichting INGKA Foundation. While the Swedish business magnate is no longer directly involved in day-to-day decision-making operations, he still sits in on meetings as senior adviser to the supervisory board.

Among his peers, the 90-year-old founder is incredibly frugal despite his massive net worth. He reportedly flies economy, stays in cheap hotels, and has driven the same Volvo for more than two decades. He also infamously moved IKEA and his family out of Sweden in the 1970s to avoid its onerous tax rates. He returned to live in his home country in 2013 after a long spell in Switzerland.

But Kamprad has also been generous with his wealth, donating to child rights, immunization, environment and wildlife, education, and medical research, with personal lifetime giving of $300 million.

Kamprad's personal wealth increased by $2.6 billion in the past year.