8 Reales - Carlos III Madura star countermark

Sumenep, a sultanate on the northeastern tip of Madura island, authorized countermarks on circulating Spanish colonial coinage as a practical solution to chronic shortages of acceptable trade silver in the Indonesian archipelago. The specific star punch applied here identified coins vetted by the sultanate's treasury — a guarantee of weight and fineness in a region where clipped and debased coinage was endemic.

Spanish milled dollars of this Carlos III period were struck primarily at Mexico City and Potosí, and were the dominant trade silver across maritime Southeast Asia long before any European colonial power attempted to displace them.