A. Few people pay much attention to coins; we take them for granted. Since the advent of paper currency and the abandonment of a monetary system based on intrinsic or actual value, they have been demoted to the status of change: what is left when you have paid for something with 'paper' money. There is even a belief that they will one day be obsolete, as will paper or plastic notes, and money will at last have achieved the pure status of a mathematical formulation, a system of electronic credits and debits.
B. In the modern media environment, the sheer number of visual images is overwhelming, but it makes one stop to think that coins are among the most durable of our artefacts, and future archaeologists will scrutinise coins in order to learn about their distant ancestors. This is exactly the way ancient coins have informed us for over four millennia. There are thousands of different coins, each designed to carry meaning as well as value, tiny but rich sources of documentary evidence about events and cultural attitudes, frequently produced with exquisite craftsmanship.
C. Coins in Europe date from 2,500 to 2,700 years ago, and seem to have originated in the ancient kingdom of Lydia, in what is now Turkey. Before coins, trade was based on barter: the direct trade of commodities. Barter required the physical presence of both commodities that were being traded. Metal coins were far more portable, and not subject to the same spoilage on long sea journeys as a commodity like grain might be if it became wet. However, they could also be accumulated, and these hoards could be stolen. Coins were therefore a temptation to criminals. The Greeks, however, were the first to realise the full potential of the new invention. They were a trading people of seafarers. Their civilisation, which was composed of dozens of city-states, was highly decentralised. Despite the potential for theft, the Greeks realised that they could benefit enormously from a system that used coins, because it meant that they no longer had to carry goods with them to barter.
D. The value of coins was generally based on the intrinsic value of the metal they were made of. At first this was mostly silver, and this meant that the discovery of silver mines on Greek territory actually increased the quantity of money they could produce. Had the Greek mining been on a larger scale, it could have caused problems similar to those faced by the Spanish centuries later, when so much gold from the New World was brought into their economy that it resulted in serious inflation. One advantage of intrinsic value was that coins could be weighed to determine the amount of metal they contained, so that the only thing an issuing state had to guarantee was the purity of the metal to prevent accusations of fraud and cheating, which could cause fighting and unrest. This was quite difficult to do, especially with coins made of gold, until Archimedes realised that different metals have different weight-volume ratios, and that by measuring the amount of displacement when coins were immersed in water, it was possible to establish whether gold was alloyed with silver.
E. All ancient coins were made by hand using engraved metal moulds. Many hundreds of coins were made, and as a result the moulds often cracked and new ones had to be engraved. This explains the endless variety encountered in coins with the same designs because the moulds had to be remade repeatedly, by many different artisans. One of the distinctive features of coins, in fact, is that they are the work of anonymous craftsmen, and yet each coin is an intimate reflection of the character of its city of origin. It was the Greeks who realised that coins could have a double function, as a unit of value and as a symbol of the identity of the city that issued them. The Greek view of life was deeply motivated by a spirit of competition, and coins, which circulated around the trading world, were a way of advertising the qualities of each particular city-state.
F. Interestingly, Greek coins from the city of Athens, which was the home of the greatest sculptors of the classical period, seem to have been completely disconnected from the high sculptural tradition. The beautiful features of the city's patron, Athena (with her owl on the reverse of the coin), seem to have been repeated virtually unaltered for many years. Perhaps this was because the Athenian currency had grown increasingly to be the international standard and, like the US dollar today, a uniform design implied integrity.
G. One side of a coin was always occupied by the head of a divinity, so it was a relatively small step, at around 323 BC, for Greek coins to replace that head with the portrait of the reigning monarch, a tradition that has continued in monarchies to the present day. Republics may have either symbolic heads - going back to the older tradition of divinities - or the features of a distinguished past head of state. The Romans adopted the Greek practice of coin design and as a result, the features of many great Romans have survived and are known to modern generations, despite the fact that the art of portrait painting was completely lost for more than a millennium following the fall of the Roman Empire.