A Question About The Achaemenid Empire And Their Coins.

The Achaemenid Empire, also known as the Medo-Persian Empire, was not the first empire in the region - though it was one of the most internally coherent, and was also the first to have it's capital city and origins in what is now Iran.

The ancestry of the ruling hose of the Empire is the subject of much debate, largely because the records of the Persians themselves have mostly been lost and the few that survive are of questionable reliability. It is best to describe Achaemenes as "mythical" rather than "pretend" - in the same sense that King Arthur is "mythical".

Cyrus the Great did not "found" the Persian state, but he did take it from a small tribal city-state and turned it into an Empire - much as Philip II and Alexander III did for Macedonia a couple of centuries later. Lydia, in what is now western Turkey, was just one of numerous areas he conquered. Prior to the Persian invasion, Lydia was inhabited by a mixture of native peoples (mainly the descendants of Hittites that had conquered the place a thousand years earlier, known as "Lydians" or "Sfard" in their own language) and Greek colonists.

The Persians did not strike any coinage of their own until they conquered Lydia, which was already striking coins prior to the conquest. While the gold darics are found throughout the eastern Mediterranean and beyond, the siglos is rarely found outside of western Turkey, meaning it was primarily intended as a replacement for the Lydian coinage, rather than as an empire-wide monetary unit.


The name "daric" for the gold coin is well attested; it is even found in the Bible (in Hebrew form) as "adarkonim". Recall that in those days, gold coins were traded by weight, so "daric" was the name of both the coin itself and the amount of gold that was needed to make 1 coin. The word was not used to measure any other substance; the daric weighed 1 old Babylonian shekel and "shekel" would have been used as the name of the unit of weight.

"Siglos" (plural "sigloi"), the name given to the silver coins, is somewhat more convoluted. The Lydians had a unit of weight called the "siglos", which at about 10 grams was actually twice the weight of the Persian coin that now bears that name; more properly, the coins should perhaps then be called "half-sigloi", though getting people to change things at this late stage seems redundant.

The designs of the two coins were the same, even made from the same dies. The weights were different, of course; the daric is heavier because gold is denser than silver. The rate of exchange was fixed, at 20 sigloi (that's the coin, not the weight) to the daric.

The "siglos" was a different weight to the greek "drachm"; the drachm weighed slightly less. The exchange rate was 25 drachms to the daric.

You're welcome.

One part of your question I did not touch on was your comment on the use of "dram" as a unit of measurement of liquids. The origin of the word "drachm", and its changing meaning down through the millennia, is an interesting story in itself.

As the Internet is a mostly silent medium, perhaps a brief note on pronunciation is in order first. "Drachm", in Greek, is spelled with the letter "chi". This letter resembles the letter X but does not have a readily pronounceable equivalent in English; it is close to the "ch" in German (ich) or Scottish (loch), but is unlike the "ch" in most English words, such as "church". The closest English comes to the "correct" pronunciation of "Greek-chi-ch" is in certain Greek loanwords, such as "christ". When talking about Greek coins, I have heard the word "drachm" pronounced "drakk-em" and this is how I usually pronounce it myself to avoid confusion, though omitting the hard-to-pronounce letter entirely and saying "drahm", "dram" or "drah-hum" are all apparently acceptable.

The Greek word "drachm" originally meant "handful". It is a reference to the primitive money the ancient Greeks used to use, before they invented coinage: iron sticks. One iron stick was called an "obol"; a "drachm" was the number of iron sticks you could comfortably hold in one hand. Specifically, six. Six obols to the drachm remained the basic subdivision of Greek and Greek-derived coinage until the drachm itself became obsolete.

Once they started making much more convenient coinage out of precious metals, they had to decide on how much silver was equivalent to one iron drachm. Different parts of the Greek world had different standards, depending on the relative scarcity of the two metals. On the island of Euboea in eastern Greece, the drachm was about six grams; on the island of Aegina just to the south, it was closer to four grams. These two rival standards became the dominant measurements throughout the Greek world, until Macedonian hegemony forced everyone to adopt the lighter standard.

The Parthians inherited most of the eastern Greek Seleucid empire, and with it the drachm silver standard. This was in turn passed on to their Sassanian successors. When the Islamic Arabs conquered them in turn, the weight of the drachm (spelled "dirham" in Arabic) was enshrined in Sharia law, and they continued to use it as the memory of the "drachm" was lost to Europe during the Dark Ages.

As the West rediscovered the ancient wisdom in late Mediaeval times, largely preserved by the Arabs, the drachm (now spelled "dram" was re-invented in Europe, this time purely as a unit of weight. The unit of weight became a unit of volume in the same way that the "ounce" became the "fluid ounce" - the room-temperature volume of the equivalent weight of water.

"Dram" is still used to measure whiskey for the same reason that "troy ounces" are still used to measure precious metals and "pounds and ounces" are still used to measure babies, even in countries that have otherwise gone fully metric: tradition.