According to Forbes:
“We do not include royal family members or dictators who derive their fortunes entirely as a result of their position of power, nor do we include royalty who, often with large families, control the riches in trust for their nation.”
If they did, Fidel Castro would have been at the top of the list.
They included the daughter of the Angolan president, Isabel Does Santos, who’s entire wealth came from her daddy stealing money and assets belonging to the Angolan people and transferring to her.
http://www.forbes.com/profile/isabel-dos-santos/