The silver peso de a ocho (Spanish peso, “weight”), equivalent to eight reals (reales) in the Spanish colonies in the Americas, was probably the most widely-minted coin of the early modern period, and in Spain and its former American colonies it gave way to new units of  currency only in the 19th century. It was also a popular trade coin that circulated worldwide. The peso de a ocho was the product of a currency reform in the reign of the Catholic Monarchs, Ferdinand of Aragón and Isabella of Castile, and it was first minted - in small quantities - …