Bill Gates, who made a mere $2bn last year, has been knocked off the top of the Forbes' Rich List by his bridge partner.

The magazine's annual ranking of the globe's most minted is now topped by US investment guru Warren Buffett, who has an estimated $62bn.

Gates has been number one for an astonishing 13 years.

Also in the list is Mark Zuckerberg, the founder of Facebook, who, at 23, joins the list as the world's youngest billionaire.

He is the world's 785th richest person with a fortune of $1.5bn.

The Beeb reports that a record 1125 individuals with a combined net worth of $4.4 trillion made it into Forbes' 2008 list of billionaires.

"The reason for this explosion in wealth is that we're in the midst of a phenomenal global boom", said Steve Forbes, chief executive of Forbes magazine.

"Never before in human history have so many people in so many parts of the world advanced so quickly economically as has happened in recent years."

Two-thirds of those on the list are classified as self-made billionaires, and 50 of them are under the age of 40.

Other billionaires include Oprah Winfrey, property mogul Donald Trump, and Harry Potter author JK Rowling.