Of all the names to make it onto this list Paulo Coelho may be the most unlikely. The Brazilian author has come from almost nothing to claim his place among the great and the good - and at one point in his youth he was even sent to a mental institution by his parents. Even after his release he struggled, becoming a drifter who traveled the world and getting into drugs.
All of this changed for Coelho on a journey through Spain in the 1980s, during which he believes he had a spiritual awakening which led to him writing the globally successful novel 'The Alchemist'. It's sold more than 65 million copies and made Coelho, whose only real writing achievements previously were as a lyricist on other people's songs, a major name in the publishing industry. Many big-selling books later, half a billion dollars isn't a bad return for a guy who even his parents thought was crazy.