Meet the Richest Person Who Ever Lived

His name was Musa, and I'll bet you never heard of him.

Who is the very richest person who ever lived? It depends on how you measure it. If you measure by how many hours of labor you can purchase, then the richest person who ever lived is Carlos Slim—or rather, was Carlos Slim, whose wealth in 2009 could employ 440,000 people in Mexico, where he lives. But the economist Branko Milanovic, writing in 2011 in The Globalist, pointed out that Slim enjoyed an arguably unfair edge from being a billionaire in a low-wage country. When you consider how many people a wealthy person could employ in a comparably wealthy nation, the richest person in history was John D. Rockefeller, who at the peak of his wealth in 1937 could employ 116,000. In this instance, though, we’re talking about the Great Depression, when the price of labor was depressed.

A larger problem with both measures is that they’re based on the labor theory of value, which (as Adam Smith explained in The Wealth of Nations) designates a commodity’s value “equal to the quantity of labor which it enables [the owner] to purchase or command.” That’s an old-fashioned measure in today’s era of offshoring and automation and looming Artificial Intelligence, where the brass ring goes to the guy who makes the most money while employing, directly or indirectly, the fewest number of people. So perhaps we should keep it simple and just ask, “Who possessed the greatest wealth in human history?”

Tradition assigns this distinction to King Croesus, who ruled Lydia (a geographic area situated today in western Turkey) during the 6th century B.C. But a 2012 calculation by Forbes concluded that Croesus didn’t even crack the top 25. The richest person in history was the 14th century West African monarch Mansa [i.e., King] Musa, who reigned from 1312 to 1337. The sources of Musa’s wealth were trade, conquest, and natural resources: Musa ended up commanding about half the world’s known supply of gold. Here is an account by the Arab historian Al-Umari of Musa’s passage through Cairo during a pilgrimage to Mecca in 1324, where he gave away so much gold that he sent Egypt into a dozen-year inflationary tailspin:

From the beginning of my coming to stay in Egypt I heard talk of the arrival of this sultan Musa on his Pilgrimage and found the Cairenes eager to recount what they had seem of the Africans’ prodigal spending…. This man [Mansa Musa] flooded Cairo with his benefactions. He left no court emir nor holder of a royal office without the gift of a load of gold. The Cairenes made incalculable profits out of him and his suite in buying and selling and giving and taking. They exchanged gold until they depressed its value in Egypt and caused its price to fall. Gold was at a high price in Egypt until they came in that year. The mithqāl [i.e., price of 4.25 grams of gold] did not go below 25 dirhams and was generally above, but from that time its value fell and it cheapened in price and has remained cheap till now. The mithqāl does not exceed 22 dirhams or less. This has been the state of affairs for about twelve years until this day by reason of the large amount of gold which they brought into Egypt and spent there.

Musa was a one-man central bank, not just for his own Mali empire but for the entire world. He possessed a degree of market power that Jerome Powell can only dream about.

Musa makes a cameo appearance in my latest article for the print New Republic, a review of Milanovic’s Visions of Inequality: From the French Revolution to the End of the Cold War and Guido Alfani’s As Gods Among Men, A History of the Rich in the West. My essay considers wealth distribution through the ages and the minimal importance that the world’s great economists assigned to it from the 18th century until the turn of the 20th century. The worldly philosophers downplayed distribution partly because they lacked modern data tools but mostly because class structure was so obviously immutable. Marx, for instance, judged an excessive interest in the mathematical distribution of wealth to be “vulgar socialism.” Today, of course, economists are all vulgar socialists, scrutinizing deciles and fractiles and Gini coefficients. That’s a good thing, I believe, because this method gives us a more precise picture of what’s going on and leaves class analysis to historians and political scientists and sociologists better able to navigate its ambiguities. You can read my piece here.