4 Reales - Charles IV

Charles IV's reign over Spanish colonial coinage was administratively continuous but politically turbulent — his abdication in 1808 under Napoleon's pressure at Bayonne effectively ended legitimate Spanish authority in the Americas, and Potosí's mint continued striking in his name into 1809 largely on institutional inertia. The high-altitude mint, operating at over 13,000 feet in what is now Bolivia, had been the financial engine of the Spanish Empire since 1572.

The milled coinage from Potosí in this period replaced the earlier cob ("macuquina") tradition. Assayer initials on these pieces shifted across the production window, and attributing a specimen to a specific year often hinges entirely on that single detail.