The dynastic union of Castile and Aragon thanks to the marriage of Isabella I and Ferdinand II, the Catholic Monarchs (1474–1504), marked the beginning of a long and complex process that would eventually transform the medieval kingdoms into a single state. Currency was part of their modernization policy, designed to achieve a strong monarchy.
Reforms differed in each kingdom, as the political union was not reflected in monetary systems. The Castilian system experienced the most significant changes, with the creation of a new coin that spread beyond its borders: the excelente or “excellent”, a name chosen to emphasise its high purity.
After 1497 the excelente adopted the standard of the Venetian ducat, giving the Crown of Castile access to major international trade circuits. These coins of superlative quality, mass-produced mainly with gold from the Americas, were enormously prestigious and used for long-distance trade in Europe and on eastward routes. In fact, they were so successful that they continued to be minted for decades after the deaths of Isabella and Ferdinand, in an attempt to maintain the markets’ confidence.
They were also propaganda tools for spreading the official message of harmony between the two crowns. The monarchs were depicted as a couple, with the coats of arms of all their realms and under divine protection, symbolised by the eagle of Saint John.