Richest People Who Ever Lived ? Inflation Adjusted
 

#1 Mansa Musa I ? Net Worth $400 Billion
#2 The Rothschild Family ? $350 Billion
#3 John D. Rockefeller ? Net Worth $340 Billion
#4 Andrew Carnegie ? Net Worth $310 Billion
#5 Nikolai Alexandrovich Romanov ? Net Worth $300 Billion
#6 Mir Osman Ali Khan ? Net Worth $230 billion
#7 William The Conqueror ? Net Worth $229.5 Billion
#8 Muammar Gaddafi ? Net Worth $200 Billion
#9 Henry Ford ? Net Worth $199 Billion
#10 Cornelius Vanderbilt ? Net Worth $185 Billion
#11 Alan Rufus ? $178.65 billion
#12 Bill Gates ? Net Worth $136 Billion
#13 William de Warenne ? Net Worth $147.13 Billion
#14 John Jacob Astor ? Net Worth $121 Billion
#15 Richard Fitzalan 10th Earl of Arundel ? Net Worth $118.6 Billion
#16 John of Gaunt ? Net Worth $110 Billion
#17 Stephen Girard ? Net Worth $105 Billion
#18 A.T. Stewart ? Net Wort $90 Billion
#19 Henry Duke of Lancaster ? Net Worth $85.1 Billion
#20 Friedrich Weyerhauser ? Net Worth $80 Billion

Source

#2 The Rothschild Family – $350 Billion

Only 350 billions? must be some kind of error, i expect 1 trillion at least