Everyone knows about the super-rich. The names of the 19th century Robber Barons--Carnegie, Rockefeller, Morgan--are famous, and today's super-rich--Bill Gates, Warren Buffet, Charles and David Koch--are also well-known.
But the wealthiest person in human history is someone you likely never even heard of. And he was Black.
A depiction of Mansa Musa I in a medieval European manuscript, showing him holding up a gold nugget.
As the Roman Empire was beginning its rise from a small Italian hill town to an empire that would conquer most of Europe, another empire was beginning in the west coast of Africa. For centuries, nomadic bands had wandered through the vast Sahara Desert of northern Africa, living in small settlements near waterholes. Although the desert did not have many resources, one thing it had in abundance was salt, formed from the dried-up beds of ancient lakes. At this time, salt was more precious than gold--it was an essential diet supplement for people who lived in the hot African climate, and in pre-refrigeration days it was the only method of preserving meat and storing food. As a result, a thriving trade appeared, in which desert nomads would cut blocks of salt from the dry lakebeds and transport them by foot through the desert to the tribes living along the coast, who paid for them in gold. One of these coastal tribes was the Sonnike, who used their gold wealth (this area of Africa is still known today as the Gold Coast) to dominate and control the flow of salt from the Sahara, and established a kingdom encompassing the neighboring tribes, known as Ghana.
In the 2nd century CE, Arab traders from the east introduced the camel, and now the deep Sahara could be crossed by caravans of camels, forming a vast trading network that stretched from the Kingdom of Ghana all the way to Arabia, whose own trade network went all the way to China. The Kingdom of Ghana grew rich through the caravan trade.
One of these trading centers was a town located in the southern edge of the Sahara, in what is now the nation of Mali. This was Timbuktu, and it grew in size as the African/Arab trade continued to expand.
In 1235, a man named Sundiata Keita, a chief of the Mandinka tribe, became ruler of a small kingdom called Kangaba, to the east of Ghana on the Niger River, and over several years carried out a series of conquests that unified the local people into the Mali Empire, with Sundiata taking the name "The Lion King". By this time the kingdom of Ghana had fallen to Tuareg and Berber raiders from the Sahara, and the Mali Empire was able to invade and gain control of the gold fields, as well as the trading cities of Kumbi-Saleh (the former capitol city of Ghana), Gao, and Timbuktu. Sundiata now took the title of Mansi ("King of Kings"), and built his palace at the city of Niani. His empire stretched for over a thousand miles.
Arab traders flooded into the Mali Empire, bringing with them the Muslim religion. Sundiata's successors converted to Islam, and began building libraries and mosques in every city. Timbuktu in particular became a cosmopolitan trading center with 200,000 residents, larger than contemporary London, Rome, or Paris, and containing three universities and over 100 schools and libraries. The city was known as "The Pearl of Africa".
In 1312, the throne of Mali passed to Mansa Musa I, the grand-nephew of Sundiata. By this time, the Mali Empire controlled more than half of the entire gold and salt production in Africa, and its wealth was at its peak. Much of this was traded to Europe through Arab intermediaries, though most of the Arabs living in the Holy Land had no real knowledge of the Mali Empire.
That changed in 1324, when Musa undertook the Hajj, the pilgrimage to Mecca that all good Muslims were supposed to carry out in their lifetime. Appointing a deputy to rule in his absence, Musa departed for Mecca with an enormous caravan of camels and wagons, with 60,000 men, 12,000 slaves, and 10 tons of gold. It was said that he built a new mosque in every town he visited, including the Arab cities of Cairo, Medina, and Mecca. He gave away so much gold that he effected the local economy, causing inflated prices--which he then magnanimously corrected by borrowing gold back from Cairo merchants at enormous interest rates, the only person in history to single-handedly influence the price of gold. When he returned to Mali, he brought back dozens of Arabic scholars and thousands of books with him, which he used to establish libraries all over the empire. He also brought Arabic architects and built dozens of mosques, including the famous mud-brick Djinguereber Mosque at Timbuktu. He also imported stone masons from Spain. At the height of its power and wealth, Mali had over 400 cities, each with a mosque and library. Mansa Musa's personal wealth has been calculated at over $400 billion in today's dollars, making him the wealthiest human who has ever lived. (Only one other individual has approached this level of wealth--the oil baron John D Rockefeller had a personal fortune of $350 billion in today's dollars.)
Arabic writers were stunned by Musa's display of wealth, and wrote in awe of the power, size, and riches of the Mali Empire. Inspired by the Arab accounts, Europeans began sending expeditions to search for the fabled city of Timbuktu (the name itself became a symbol for remoteness and mystery). Stories circulated among European merchants that the buildings in Timbuktu were plated in gold, that silver glittered in the sand, and the streams contained gravel of precious gems. In reality, when European adventurers finally managed to reach Timbuktu, they found that it was surrounded by desert dunes and most of its buildings were simple mud brick. The city's wealth came from its trade, not from its surroundings.
In 1337, Mansa Musa I died, and the Kingdom of Mali passed to his son Mansa Maghan I. The Empire's power began to gradually decline, and though it remained until the 1600's, it gradually lost power to neighboring kingdoms. Control of Timbuktu passed in 1430 to the nearby Songhoi Empire, and the Mali Empire eventually faded from view.
Today, the mud-brick mosques and universities in Timbuktu are listed as UNESCO World Heritage Sites.