Spanish dollar

The real de a ocho, also known as the Spanish dollar, the eight-real coin, or the piece of eight (Spanish peso de ocho), is a silver coin, of approximately 38 mm diameter, worth eight reales, that was minted in the Spanish Empire after 1598. Its purpose was to correspond to the German thaler.

The Spanish dollar was widely used by many countries as international currency because of its uniformity in standard and milling characteristics. Some countries countersigned the Spanish dollar so it could be used as their local currency.

The Spanish dollar was the coin upon which the original United States dollar was based, and it remained legal tender in the United States until the Coinage Act of 1857. Because it was widely used in Europe, the Americas, and the Far East, it became the first world currency by the late 18th century. Aside from the U.S. dollar, several other existing currencies, such as the Canadian dollar, the Japanese yen, the Chinese yuan, the Philippine peso, and several currencies in Latin America, were initially based on the Spanish dollar and other 8-real coins. Diverse theories link the origin of the "$" symbol to the columns and stripes that appear on one side of the Spanish dollar.