During the Golden Age of Piracy (and well into the 19th Century) A Piece of Eight was a Spanish or Spanish American coin roughly that was roughly equivalent to today's dollar coin. however, However unlike today's American dollar which is worth 100 pennies, the Piece of Eight was worth, you guessed it, eight of Spain's small common demonination, the Reale (sometimes spelled "real").

As such the Piece of Eight was clearly marked with the number "8". It may sound strange to some people to have 1/8 pieces but at one time the U.S. Dollar also was divided into eight pieces or bits. Remember the nursery rhyme "two bits, four bits, six bits, a dollar"? Mexico continued to use a monetary system similar to the old Spanish Piece of Eight well into the 19th Century.

It sounds strange to use a phrase such as "piece of" to describe a coin but a quick look at the Oxford English Dictionary will make it obvious that this was common practice in the English of time. Today, we would call it an "Eight Real Piece or Coin" similar to a "$20 Gold Piece" or "Ten Mark Piece" Just about any reale might be refered incorrectly as a "Piece of Eight" but all where clearly minted as 1, 2, 4, and 8 reale pieces. Sometimes, the coins would be cut up or cut in half. so if you cut an 8 reale coin in half the two halves would each be worth four reales. Becuase the coins were made of pure silver, cutting them into pieces did little to decrease their value.

So we now know that the Piece of Eight was a standard dollar in Old Spain. Where does that leave the Doubloon and what is this Escudo that I'm talking about? Well the Escudo was a coin equivlent to two Pieces of Eight. Escudoes also came in 1, 2, 4, and 8 Escudoes pieces. A Doubloon was equal to eight Escudoes or sixteen Eight Reale coins..

The Piece of Eight was silver coin and the Doubloon is a "gold piece".

The Spanish money would've been easy to spend in the many islands of The Caribbean and becuase it was made of gold or silver, its equivilent worth was easily transferable to coins of the English Empire.

Ever wonder why the coins aren't round?

It isn't entirely because of how old they are.

Spanish money was originally minted by hand. The silver and gold was melted down and then poured out into thin strips. As the metal strips cooled they were beaten to desired thickness by hand. Then the coins were cut out to an approximate size. After this, the metal blank was placed in coin die (or stamp) and the top coin die was placed on top of the strip. Then the minter would strike the die with a hammer and the face and obverse (heads and tails) of the coin would be imbedded in the soft metal

After the coin was struck it would be weighed again and if it were over weight, small amounts of the metal would be nipped off. Later, a coin press was used. In this case the metal was placed between the two dies and they were pressed against the metal, cutting off the excess metal and making all the coins look pretty much the same.