The words algebra and algorithm both trace to one Baghdad scholar, yet almost nothing about his personal life survives beyond a bibliographer's secondhand book list.
Every figure attached to Mansa Musa's fortune, eighty camels, thousands of slaves, a specific weight of gold dust, traces back to the same handful of Arabic chroniclers, which is why historians now treat his rank as history's richest man as unverifiable rather than false.
European sailors called it an age of discovery for lands that were, in every case, already inhabited, and historians now argue the word itself was doing political work.
Only one of the five ships that set out made it all the way around the world, and only eighteen of roughly two hundred and seventy men were aboard it when it finally arrived.