On March 10, 2011, Forbes Magazine declared Mexican industrialist Carlos Slim to be the richest person in the world. This marks his second year in a row in that position. But how does his fortune of $74 billion rank against wealthy people from the past?

Who is the Richest Person of All Time?

There are two ways to compare wealth. First, we can consider non-inflated sums. Second, we can attempt the difficult task of accounting for inflation, giving a far more accurate comparison.

In terms of the first method, the richest person of all time is Bill Gates. On April 5, 1999, his fortune was estimated at an astounding $101 billion.

However, non-inflated figures mean little, especially over the course of decades or even centuries. After accounting for inflation, the richest person of all time may have been John D. Rockefeller. Rockefeller was the founder, chairman, and major shareholder of Standard Oil. On September 29, 1916, he became the first person to amass a fortune greater than $1 billion, a number which rose to $1.4 billion at the time of his death. Incredibly, his wealth was equal to about 1.53% of the U.S. economy at that time. Overall, historians believe that he amassed a fortune equivalent to $336 to $663 billion in terms of today’s dollars.

But is John D. Rockfeller really the Richest Person of All Time?

Rockefeller’s grip on the title of “The Richest Person of All Time” is controversial. Historical inflation figures are difficult to calculate and records of wealth were not always well-kept or made public. Other contenders for the title include:

• Marcus Licinus Crassus: Lived from 115 BC to 53 BC. His personal fortune, which has been estimated at 170 million sesterces, was roughly equivalent to the “entire annual income of the Roman treasury.” However, the size of his wealth is debatable and some scholars place it closer to $200 million to $2 billion.
• Musa I: Became the 10th emperor of the Malian Empire in 1312. Supposedly traveled with a huge caravan that included 60,000 men, 12,000 slaves, and 80 camels that carried between 50-300 pounds of gold dust apiece. Some value the entire caravan in excess of $400 billion in today’s dollars.
• The Rothschild Family: Some historians place the value of the mid-19th century Rothschild banking and finance dynasty at hundreds of billions or even trillions of dollars. However, this is disputed.
• Genghis Khan: He was the Khan, or emperor, of one of the largest contiguous empires in history. However, to my knowledge, no estimates for his wealth exist.

Guerrilla Explorer’s Analysis

So, there you have it. While somewhat controversial, the best evidence we have today points to John D. Rockefeller as “The Richest Person of All Time.” And with a fortune that was at least five times greater than that of any fortune today, it seems likely that he will hold that title for many more years to come.