Le doublon, était à l'origine une pièce d'or d'un double escudo soit 32 reales, d'un poids de 6.77 grammes (0.218 once Troy). Les Doublons ont été frappés en Espagne, au Mexique, au Perou, and à Nueva Granada. Le tout premier usage du terme décrivait l'excelente d'or soit à cause de sa valeur de deux ducats soit à cause du the double portrait des Rois Catholiques : Ferdinand and Isabelle.
Doubloons marked "2 S" are equivalent to $4 in US gold coins and were traded in that manner. Small 1/2 Escudo coins (similar to a US $1 gold piece) have no value on them but were worth a Spanish Milled Dollar in trade.
In Spain, doubloons were current up to the middle of the 19th century. Isabella II of Spain replaced an escudo-based coinage with decimal reales in 1859, and replaced the 6.77 gram doblón with a new heavier doblón worth 100 reales and weighing 8.3771 grams (0.268 troy ounces). The last Spanish doubloons (showing the denomination as 80 reales) were minted in 1849. After their independence, the former Spanish colonies Mexico, Peru and Nueva Granada continued to mint doubloons.
Doubloons have also been minted in Portuguese colonies, where they went by the name dobrão, with the same meaning.
In Europe the doubloon became the model for several other gold coins, including the French Louis d'or, the Italian doppia, the Swiss duplone, the Northern German pistole, and the Prussian Friedrich d'or.