Pergamon (Ancient Greek: or ), or Pergamum, was an ancient Greek city in modern-day Turkey, in Mysia, today located 16 miles (26 km) from the Aegean Sea on a promontory on the north Side of the river Caicus (modern day Bakrcay), that became the capital of the Kingdom of Pergamon during the Hellenistic period, under the Attalid dynasty, 281133 BC.
Pergamon was cited in the book of Revelation as one of the seven churches of Asia. Today, the main sites of ancient Pergamon are to the north and west of the modern city of Bergama. The Attalid kingdom was the rump state left after the collapse of the Kingdom of Thrace. The Attalids, the descendants of Attalus, father of Philetaerus who came to power in 281 BC following the collapse of the Kingdom of Thrace, were among the most loyal supporters of Rome in the Hellenistic World. Under Attalus I (241-197 BC), they allied with Rome against Philip V of Macedon, during the first and second Macedonian Wars, and again under Eumenes II (197-158 BC), 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.