From BiblePortal Wikipedia

Watson's Biblical & Theological Dictionary [1]

a city of Troas, very considerable in the time of John the evangelist,  Revelation 2:12-13 . This city was, for the space of one hundred and fifty years, the capital of a kingdom of the same name founded by Philetaerus, B.C. 283; who treacherously made use of the treasures committed to his care by Lysimachus after the battle of Ipsus, and, seizing on Pergamus, established an independent kingdom. After Philetaerus were five kings of the same race; the last of whom, Attalus Philopater, left his kingdom, which comprehended Mysia, AEolis, Ionia, Lydia, and Caria, to the Roman empire; to which it belonged when the first Christian church was established there. This church early became corrupted by the Nicolaitans, for which it was reproved by St. John, and charged quickly to repent,  Revelation 2:14-16 . Pergamus, now called Bergamo, like most other places which have been cursed by the presence of the Turks, is reduced to comparative decay, containing a poor population, who are too indolent or too oppressed to profit by the richness of their soil and the beauty of the climate. The number of inhabitants, however, is still said to amount to thirty thousand, of whom three thousand are Greek Christians. Many remains of former magnificence are still to be found; among which are those of several Christian churches. It is about sixty miles north of Smyrna. The celebrated physician Galen was a native of this place.