Mansa Musa (14th century)
With an estimated net worth of 415 Billion dollars. Monta Musa, the first emperor of Mali and King of Timbuktu, is at number 6 in this list, he controlled the Mali Empire and the Ghana Empire and conquered much of West Africa during his reign in the 14th century.
One of his titles was lord of mines, and he owned more than half the world’s supply of gold at a time that there was a hugely increased demand for the commodity, and he also controlled vital trade routes between the West African coast and the Mediterranean.
He built schools, mosques, and even a major University, all of which became his legacy many years after he died and some of which are still standing now.
He’s also known for a fabulous pilgrimage he once made to Mecca in a caravan stretching as far as the eye could see with an entourage of tens of thousands of people donating and spending so much money. When they stopped in Cairo that it caused instant inflation, and it took years for the local economy to recover from the shock.