8 Reales - Philip II

Potosí's Cerro Rico — the "rich hill" — was supplying roughly half the world's silver by the 1570s, and this coin moved through global trade circuits that no European mint could match in volume. The Manila Galleon trade sent pieces-of-eight directly from Acapulco to Chinese merchants who accepted little else; by the late sixteenth century, Spanish colonial silver had become the closest thing to a world reserve currency.

The Potosí mint operated under chronic quality control failures throughout Philip II's reign. An infamous fraud scandal in the 1640s — decades later, but rooted in practices established in this period — revealed that assayers had been systematically debasing the silver. These early cobs were cut and hammered by hand, making weight and fineness the only real guarantees of value.