Rising in the 13th century across what is now Mali, Senegal and Guinea, the Mali Empire grew extraordinarily wealthy by controlling West Africa's trade in gold and salt. Its most famous ruler, Mansa Musa, is remembered as one of the richest people of his age — perhaps of all history; his wealth rested on the gold mines he controlled.

In 1324 Mansa Musa, a Muslim ruler, went on pilgrimage to Mecca. Along the way a caravan of tens of thousands of people, camels laden with gold and lavish gifts drew attention. Passing through Cairo, he gave away and spent so much gold that its value in the city fell for years — a rare, documented case of one ruler's personal wealth shaking a regional economy.

This journey brought Mali onto the agenda of the Mediterranean world. In the famous Catalan Atlas drawn a few decades later (1375), Mansa Musa was depicted as a ruler seated on his throne holding a gold nugget — an early sign of Europe's perception of West Africa as a source of wealth.

Returning from pilgrimage, Mansa Musa brought scholars and architects to Mali. The cities of Timbuktu and Djenné, with their mud-brick mosques and madrasas, became important centres of Islamic learning; institutions such as Sankoré in Timbuktu housed thousands of manuscripts. This is proof that, in the medieval world, sub-Saharan Africa too was a geography of scholarship and commerce.