Pergamon or Pergamum was an ancient Greek city, in Mysia, north-western Anatolia, 16 miles from the Aegean Sea, located on a promontory on the north side of the river Caicus (modern day Bakirçay), that became an important kingdom during the Hellenistic period, under the Attalid dynasty, 282–129 BC. The Attalid kingdom was the rump state left after the collapse of the Lysimachian Empire.
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. When Attalus III died without an heir in 133 BC he bequeathed the whole of Pergamon to Rome, in order to prevent a civil war.
The Great Altar of Pergamon is in the Pergamon Museum, Berlin. The base of this altar remains on the upper part of the Acropolis. Other notable structures still in existence on the upper part of the Acropolis include: a Hellenistic theater with a seating capacity of 10,000; the Sanctuary of Trajan (also known as the Trajaneum); the Sancturay of Athena; the Library; royal palaces; the Heroon; the Temple of Dionysus; the Upper Agora; and the Roman baths complex. Pergamon's library on the Acropolis (the ancient Library of Pergamum) is the second best in the ancient Greek civilisation, after that of Alexandria(see Royal Library of 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 pergaminus or pergamena (parchment) after the city. This was made of fine calf skin, a predecessor of vellum. The library at Pergamom was believed to contain 200,000 volumes, which Mark Antony later gave to Cleopatra as a wedding present. The lower part of the Acropolis has the following structures: the Upper Gymnasium, the Middle Gymnasium, the Lower Gymnasium, the Temple of Demeter, the Sanctuary of Hera, the House of Attalus, the Lower Agora and the Gate of Eumenes.
Three kilometers south of the Acropolis was the Sanctuary of Asclepius (also known as the Asclepeion), the god of healing. In this place people with health problems could bath in the water of the sacred spring, and in the patients' dreams Asklepios would appear in a vision to tell them how to cure their illness. Archeology has found lots of gifts and dedications that people would make afterwards, such as small terracotta body parts, no doubt representing what had been healed. Notable extant structures in the Asclepeion include the Roman theater, the North Stoa, the South Stoa, the Temple of Asclepius, a circular treatment center (sometimes known as the Temple of Telesphorus), a healing spring, an underground passageway, a library, the Via Tecta (or the Sacred Way, which is a colonnaded street leading to the sanctuary) and a propylon.
Pergamon's other notable structure is the Serapis Temple (Serapeum) which was later transformed into the Red Basilica complex (or Kizil Avlu in Turkish), about one kilometer south of the Acropolis. It consists of a main building and two round towers. In the first century AD, the Christian Church at Pergamon inside the main building of the Red Basilica was one of the Seven Churches to which the Book of Revelation was addressed.