- Bill Gates - €86bn
Gates founded software giant Microsoft in 1975 with Paul Allen and changed the face of home and business computing forever. He has topped the Forbes list of the 400 richest Americans for 24 years and, with wife Melinda, chairs the world's largest private charitable foundation. Forbes' real-time tracking of his wealth shows it has since surpassed the $90bn mark, helped no doubt by the launch of a new energy fund in 2016.
- Warren Buffett - €75.6bn
The so-called Oracle of Omaha still lives in the same Omaha, Nebraska home he purchased in 1958 for $31,500 and, to date, has given away $32bn of his huge fortune. His Berkshire Hathaway conglomerate - which owns at least 60 companies - continues to boom with its share price topping $300,000 in December. The growth of Buffett's wealth has been even more rapid than that of his good friend Bill Gates over the past year.
- Jeff Bezos - €72.8bn
Amazon is finding a way into every part of our lives and its founder's wealth has grown so much since the official Forbes 2017 listing - to over $100bn - that he is now likely to be the richest person on the planet. Apart from his 17pc stake in the online retailer he founded in a Seattle garage in 1994, Bezos also owns The Washington Post and space travel company Blue Origin.
- Amancio Ortega - €71.3bn
Europe's richest man cofounded Inditex - the parent of fashion retail giant Zara - with his ex-wife Rosalia Mera in 1975. The Spaniard enjoys dividends of more than $400m and has invested wisely in property in Europe and the US.
- Mark Zuckerberg - €56bn
Facebook's share price has more than quadrupled since it went public in 2012 and with it, the wealth of its founder Mark Zuckerberg. The 2017 Forbes listing of $56bn is long since out of date and Zuckerberg, who started the social network in 2004 as a student before dropping out of Harvard, has since added at least $20bn to his worth.
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