Our list of the ten richest, based on scholarly estimates and adjusted for inflation, includes entrepreneurs, warriors, and robber barons. We did not include monarchs, whose vast wealth is considered public.
Bill Gates, Warren Buffett, and Carlos Slim are the only living men who crack the list -- and that's only counting their net worth at bubble peaks in 1999 and 2007.
#8 John Jacob Astor
Peak fortune: $121 billion
Source of wealth: A successful fur trader, he established a near monopoly within the U.S. by around 1800. He subsequently switched trades and went on to investing in real estate, focusing on New York City.