In 1252 the Republic of Florence created the florin, a gold coin that soon became standard currency across Europe in the 13th and 14th centuries. With high purity and easily recognisable images—a fleur-de-lis and Saint John the Baptist—florins circulated throughout the continent and the Mediterranean world and were imitated by many states.
One of them was the Crown of Aragon, which had become a Mediterranean power when it annexed the Catalan counties and the kingdoms of Valencia, Mallorca, Sardinia and Sicily, a setting where influences (and competition) came from Italy and France. In 1346, faced with the need for a coin suitable for large-scale trade, Peter IV adopted the florin.
The Aragonese florin was identical to the original in every respect except for the legend, which identified the king of Aragon, ARAGO REX, as the issuing authority. It was destined to circulate throughout the territories of the Aragonese crown. This was a novel development, for unlike Castile, which had implemented a uniform monetary system in its realms, the lands ruled by Aragon each had their own system with different coins.
Well into the 15th century, the florin ceased to be a reliable coin. Its fall from favour led to the rise of the Venetian ducat, which replaced the florin as international currency.