In July 1324, a caravan came out of the Sahara and into Cairo, and the city had never seen anything like it. Thousands of people moved in procession. Camels carried loads of raw gold. Ahead of the column walked five hundred enslaved men, and by the account that survives, each carried a staff of gold weighing several pounds. At the centre was Musa I, ruler of Mali, on pilgrimage to Mecca.
He stayed three months. He was, by every description, extravagantly generous. He gave gold to officials, to people experiencing poverty, to anyone who came to his lodging. He bought whatever caught his attention and paid above the asking price. Cairo's merchants, who were not naive people, could not believe their luck.
Then the market broke.
So much gold had entered the city in so short a time that the dinar lost a substantial share of its value. When the Egyptian historian al-Umari came to write about the visit more than a decade later, he reported that the price still had not fully recovered. One man's travel budget had dislocated the currency of the richest city in the Mediterranean world, and it had not been an act of policy. It was an accident of scale.
Hold that image, because we are going to need it.
Six hundred and ninety-nine years later, a small business owner in Kampala wants to pay a supplier in Kigali. The two cities are a day's drive apart. The money leaves her mobile wallet in Ugandan shillings, converts to US dollars, travels to a correspondent bank in New York, converts again, and arrives in Rwandan francs some days later, lighter by a margin she has learned not to calculate too closely. Nothing about the transaction is illegal, broken, or unusual. This is simply how African money moves between African countries.
Mali's ruler had the capacity to transport enough gold to influence global prices. His descendants cannot transport a hundred dollars across a mutual border without seeking permission from a bank situated in a different continent.
