Sardis, the capital of the ancient kingdom of Lydia, the seat of a conventus under the Roman Empire, and the metropolis of the province Lydia in later Roman and Byzantine times, was situated in the middle Hermus valley, at the foot of Mt. Tmolus, a steep and lofty spur of which formed the citadel. It was about 21/2 m. S. of the Hermus. The earliest reference to Sardis is in the Persae of Aeschylus (472 B.C); in the Iliad the name Hyde seems to be given to the city of the Maeonian (i.e. 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 Maeonians, but that it became so amid the changes which produced the powerful Lydian empire of the 8th century b.c The city was captured by the Cimmerians in the 7th century, by the Persians and by the Athenians in the 6th, and by Antiochus the Great at the end of the 3rd century. Once at least, under the emperor Tiberius, in A.D. 17, it was destroyed by an earthquake; but it was always rebuilt. It was one of the great cities of western Asia Minor till the later Byzantine period.
As one of the Seven Churches of Asia, it was addressed by the author of the Apocalypse in terms which seem to imply that its population was notoriously soft and fainthearted. Its importance was due, first to its military strength, secondly to its situation on an important highway leading from the interior to the Aegean coast, and thirdly to its commanding the wide and fertile plain of the Hermus.
The early Lydian kingdom was far 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 woollen stuffs and carpets. The statement that the little stream Pactolus which flowed through the market-place rolled over golden sands is probably little more than a metaphor, due to the wealth of the city to which the Greeks of the 6th century B.C. resorted for supplies of gold; but trade and the organization of commerce were the real sources of this wealth. After Constantinople became the capital of the East a new road system grew up connecting the provinces with the capital. Sardis then lay rather apart from the great lines of communication and lost some of its importance. It still, however, retained its titular supremacy and continued to be the seat of the metropolitan bishop of the province of Lydia, formed in A.D. 295. It is enumerated as third, after Ephesus and Smyrna, in the list of cities of the Thracesian thema given by Constantine Porphyrogenitus in the 10th century; but in the actual history of the next four centuries it plays a part very inferior to those of Magnesia ad Sipylum and Philadelphia, which have retained their pre-eminence in the district. The Hermus valley began to suffer from the inroads of the Seljuk Turks about the end of the 11th century; but the successes of the Greek general Philocales in 1118 relieved the district for the time, and the ability of the Comneni, together with the gradual decay of the Seljuk power, retained it in the Byzantine dominions. The country round Sardis was frequently ravaged both by Christians and by Turks during the 13th century. Soon after 1301, the Seljuk Turks overran the whole of the Hermus and Cayster valleys, and a fort on the citadel of Sardis was handed over to them by treaty in 1306. The city continued its decline until its capture (and probable destruction) by Timur in 1402.
The ruins of Sardis, so far as they are now visible, are, chiefly of the Roman period; but though few ancient sites offered better hope of archeological finds, the necessity for heavy initial expenditure was a deterrent (e.g. to H. Schliemann).