Pergamus, an ancient city of Lysia, in Asia Minor, was situated on the N. bank of the Caicus. which at that time communicated directly with the sea. The town centred round the Acropolis, which was on a hill behind it. Founded by a colony of Greek emigrants, it had already become important in the early part of the 3rd century B.C. As part of the territory conquered by Alexander the Great, it was ruled by his general Lysimachus; but Philetcerus revolted, and made it an independent state, and such it remained till 133 B.C., when Attains'III. bequeathed it to the Roman Empire, of which it became a province. Under the Byzantine rule it gradually fell into decay; but many things testify to its former greatness. It had a library second only to that of Alexandria, and St. John speaks of its church as one of the seven churches in Asia. There are remains of noble architecture in and about the town of Bergamah, which now occupies its site. Pergamus gives us the word "parchment," that substance having been probably first used there.