Pergamos or Pergamum (Turkish Bergama) was a Greek city, in northwestern Anatolia, 16 miles from the Aegean Sea, located on a promontory on the north side of the river Caicus (modern day Bakir), that became an important kingdom during the Hellenistic period, under the Attalid dynasty, 282–129 BC.
The Attalids, the descendants of Attalus, the father of Philetaerus who came to power in 282 BC, were among the most loyal supporters of Rome among the Hellenistic successor states. Under Attalus I, they allied with Rome against Philip V of Macedon, during the first and second Macedonian Wars, and again under Eumenes II, against Perseus of Macedon, during the Third Macedonian War. For support against the Seleucids, the Attalids were rewarded with all the former Seleucid domains in Asia Minor.
The Attalids ruled with intelligence and generosity. Many documents survive showing how the Attalids would support the growth of towns through sending in skilled artisans and by remitting taxes. They allowed the Greek cities in their domains to maintain nominal independence. They sent gifts to Greek cultural sites like Delphi, Delos, and Athens. They defeated the invading Celts. They remodeled the acropolis of Pergamum after the Acropolis in Athens. The Great Altar of Pergamon is in the Pergamon Museum of Berlin.
Pergamos had the second best library in the ancient world, after Alexandria. When the Ptolemies stopped exporting papyrus, partly because of competitors and partly because of shortages, the Pergamenes invented a new substance to use in codices, called pergamum or parchment after the city. This was made of fine calf skin, a predecessor of vellum and paper.
In the first century AD, the Christian Church at Pergamos was one of the Seven Churches to which the Book of Revelation was addressed.