From WikipediaSardis or Sardes was an ancient city at the location of modern Sart in Turkey's Manisa Province. Sardis was the capital of the ancient kingdom of Lydia, one of the important cities of the Persian Empire, the seat of a proconsul under the Roman Empire, and the metropolis of the province Lydia in later Roman and Byzantine times.
The earliest reference to Sardis is in The Persians of Aeschylus (472 BC); in the Iliad, the name Hyde seems to be given to the city of the Lydian chiefs and in later times Hyde was said to be the older name of Sardis, or the name of its citadel. It is, however, more probable that Sardis was not the original capital of the Lydian, but that it became so amid the changes which produced the powerful Lydian empire of the 8th century BC.
The city was captured by the Cimmerians in the 7th century BC, by the Persians in the 6th, by the Athenians in the 5th, and by Antiochus III the Great at the end of the 3rd century BC. In the Persian era, Sardis was conquered by Cyrus the Great and formed the end station for the Persian Royal Road which began in Persepolis, capital of Persia. Sardis was the site of the most important Persian satrapy. During the Ionian Revolt, the Athenians burnt down the city. Sardis remained under Persian domination until it surrendered to Alexander the Great in 334 BC.
The early Lydian kingdom was very advanced in the industrial arts and Sardis was the chief seat of its manufactures. The most important of these trades was the manufacture and dyeing of delicate woolen stuffs and carpets. The stream Pactolus which flowed through the market-place "carried golden sands" in early antiquity, which was in reality gold dust out of Mount Tmolus. It was during the reign of King Croesus that the metallurgists of Sardis discovered the secret of separating gold from silver, thereby producing both metals of a purity never known before.This was an economic revolution, for while gold nuggets panned or mined were used as currency, their purity was always suspect and a hindrance to trade. Such nuggets or coinage were naturally occurring alloys of gold and silver known as electrum and one could never know how much of it was gold and how much was silver. Sardis now could mint nearly pure silver and gold coins, the value of which could be — and was — trusted throughout the known world. This revolution made Sardis rich and Croesus' name synonymous with wealth itself. For this reason, Sardis is famed in history as the place where modern currency was invented.
Disaster came to the great city under the reign of the emperor Tiberius, when in AD 17, Sardis was destroyed by an earthquake, but it was rebuilt with the help of ten million sesterces from the Emperor and exempted from paying taxes for five years. It was one of the great cities of western Asia Minor until the later Byzantine period.