Spanish dollar – This coin, also known as the piece of eight, was made of silver and was in use from 1497 to 1864. It was also known as the real de ocho, being worth eight reals. It was one of the purest coins, slightly lighter than a British crown. It was traded at four and half shillings in England and five shillings in the American colonies. Because of the lack of small coinage in the colonies, it was often divided up into eight pieces, the reason for its popular name. The Spanish dollar was widely used as the first international currency because of its uniformity in standard and milling characteristics. They often originated from the Spanish colonies, where the milling technology not available. Although containing the same value in silver, not being milled and being more crudely minted made them easier to clip.
Real – This coin was made of silver and was minted in denominations of half, one, two, and eight real coins. The eight real coin was know as the real de ocho or piece of eight. It was minted from the mid 14th century until 1868, when it was replaced by the peseta.
Doubloon – This gold coin was also known as the double escudo, being worth two escudos. In 1537 they replaced the heavier gold coin called the excelente, which was also known as the ducat. Doubloons were minted in Spain and the Spanish American viceroyalties from 1537 until 1849, although they continued to be minted in the former Spanish Viceroyalties of Mexico, Peru and New Granada after that date.
Escudo – This was a gold coin which was first introduced in about 1536 and issued until 1833. They were initially worth 16 reales. They were minted in denominations of half, one, two (doubloon), four and eight escudos. Like the real, the escudo was eventually replaced by the peseta. Most were minted in Spain.
Maravedíes – This was the smallest denomination of coin, there being 64 in a Spanish dollar. The name derives from the Arabian Almoravid dinar, originally a silver or gold coin. In 1537, just after the forming of colonies in the New World, it became the Spanish coin with the lowest value. The maravedíes was made of copper and there were 34 in a real. They were widespread in the Spanish colonies and useful for small transactions. This coin was in use until 1847.
Summary of values:
1 dollar = 8 reales = 272 maravedíes
1 doubloon = 2 escudos = 4 dollars = 32 reales = 1088 maravedíes