7. Albert von Thurn und Taxis

•  Net Worth: $1.5 B                                                                      
•  Source of Wealth: diversified
•  Citizen: Germany
•  Age: 30

Albert von Thurn und Taxis first appeared in Forbes' billionaire rankings at age 8 but officially inherited his fortune in 2001 on his 18th birthday. In June 2008, he received an M.A. in economics and theology from the University of Edinburgh in Scotland. His assets include real estate, art and 36,000 hectares of woodland in Germany, one of the largest forest holdings in Europe.