Spanish dollar

The Spanish dollar, originally known as the piece of eight (Spanish: real de a ocho, peso duro, peso fuerte or peso), and much later also dólar is a silver coin of approximately 38 mm (1.5 in) diameter worth eight Spanish reales. It was minted in the Spanish Empire following a monetary reform in 1497 with content 25.563 g (0.8219 ozt) fine silver. It was widely used as the first international currency because of its uniformity in standard and milling characteristics. Some countries countermarked the Spanish dollar so it could be used as their local currency.

Because the Spanish dollar was widely used in Europe, the Americas, and the Far East, it became the first world currency by the 16th century.

The Spanish dollar was the coin upon which the original United States dollar was based (at 0.7735 troy ounces or 24.06 grams), and it remained legal tender in the United States until the Coinage Act of 1857. Many other currencies around the world, such as the Japanese yen and the Chinese yuan, were initially based on the Spanish dollar and other 8-real coins. Most theories trace the origin of the "$" symbol, which originally had two vertical bars, to the pillars of Hercules wrapped in ribbons that appear on the reverse side of the Spanish dollar.

The term peso was used in Spanish to refer to this denomination, and it became the basis for many of the currencies in the former Spanish viceroyalties, including the Argentine, Bolivian, Chilean, Colombian, Costa Rican, Cuban, Dominican, Ecuadorian, Guatemalan, Honduran, Mexican, Nicaraguan, Paraguayan, Philippine, Puerto Rican, Peruvian, Salvadoran, Uruguayan, and Venezuelan pesos. Of these, "peso" remains the name of the official currency in the Philippines, Mexico, Cuba, the Dominican Republic, Colombia, Chile, Argentina, and Uruguay.

In the 16th century, Count Hieronymus Schlick of Bohemia began minting a silver coin known as a Joachimsthaler or simply thaler, named after Joachimsthal, the valley in the Ore Mountains where the silver was mined. The word thaler was borrowed into English as dollar and came to be used for a number of European coins, including the Spanish peso or piece of eight.

The Joachimsthaler weighed 451 Troy grains (29.2 g; 0.94 ozt) of silver. These coins' success led to similar thalers being minted in Burgundy and France and their ultimate succession by the long-lived Reichsthaler of the Holy Roman Empire, used from the 16th to 19th centuries, of 25.984 g (0.8354 ozt) pure silver.

The Netherlands also introduced its own dollars in the 16th century: the Burgundian Cross Thaler (Bourgondrische Kruisdaalder), the German-inspired Rijksdaalder, and the Dutch lion dollar (leeuwendaalder). The latter coin was used for Dutch trade in the Middle East, in the Dutch East Indies and West Indies, and in the Thirteen Colonies of North America.

For the English North American colonists, however, the Spanish peso or "piece of eight" has always held first place, and this coin was also called the "dollar" as early as 1581. After the Declaration of American Independence, the United States dollar was introduced in 1792 at par with this coin at 371.25 grains = 0.7735 troy ounces = 24.0566 g. Alexander Hamilton arrived at these numbers based on a treasury assay of the average fine silver content of a selection of worn Spanish dollars.