Zheng He's Treasure Fleets
Decades before Columbus, Ming China sent the admiral Zheng He across the Indian Ocean with 'treasure fleets' of hundreds of ships and tens of thousands of men — vessels so vast that Columbus's would have fit upon their decks. China reached East Africa and could plausibly have sailed further still. Then, abruptly, the emperors called the fleets home, burned the records, and turned inward — leaving the oceans, and the coming age of exploration, to Europe.
The path or medium of exchange moves, and a place or power rises or declines because it sits on or off the new route.