Mansa Musa was the ruler of the West African empire of Mali, which sat on top of huge supplies of gold and salt. In the 14th century his kingdom controlled some of the most important trade routes in the world. Modern historians have tried to estimate his fortune and basically given up - there is no good way to compare wealth across 700 years.
In 1324 Musa set off on a pilgrimage to the holy city of Mecca, far across the Sahara desert. His caravan was enormous: thousands of attendants, soldiers, and slaves, plus a long line of camels and horses loaded with gold dust and bars. He stopped in Cairo and gave away so much gold to the poor and to anyone who helped him that the value of gold in Egypt plummeted.
Back home, Musa used his wealth to build mosques, libraries, and universities, especially in the city of Timbuktu, which became a famous center of learning. Scholars traveled there from across the Muslim world to study and teach.
