During the Wars of the Diadochi, a long and bloody war fought by Alexander's generals over his empire after his death, Lysimachus held on to the province Thrace which included Pergamos. He placed Philetareus as commander of Pergamos. Philetareus served Lysimachus faithfully until 282 BC when, probably, over court intrigues involving Lysimachus’ third wife, Arisone, he decided to defect.

He went to Seleucus, one of Lysimachus’ chief rivals and ruler over the province of Babylonia, and offered himself and the city of Pergamon to him. Seleucus defeated Lysimachus in the Battle of Corupedium and killed him in 281 BC. Seleucus himself was killed a few months later and though partially under Seleucid rule Philetaerus enjoyed considerable autonomy and ruled Pergamon on his own.

Because Pergamos had been a hiding place for Lysimachus’ considerable wealth Philetaerus had enough money at his disposal to extend his rule beyond the city of Pergamos to the surrounding areas. Money meant that he could fund troops and broker peace with neighbors thus creating alliances that would ensure protection.

He expanded the city, strengthened its fortifications, and built some of its most opulent temples, one to Demeter on the acropolis and another to Athena who was the patron deity of Pergamos. Philetaerus was a eunuch and left no children when he died. He ruled Pergamos for forty years and his nephew and adopted air Eumenes succeeded him. Eumenes rebelled against the Seleucids and defeated Antiochus I Soter in battle near Sardis, the stronghold of the Lydians.

He expanded his territory and established the Kingdom of Pergamon, building garrisons in the surrounding region. Under Eumenes and successive Attalid kings, Pergamos continued to flourish. When its last King, Attalus III bequeathed his kingdom to the Romans in 133 BC, Pergamos became the capital of the province of Asia.

Roman Proconsuls that ruled Pergamos were vested with a broad double-edged sword as a symbol of their authority. The supreme court of Asia was also located in Pergamos. The court tried only the most serious cases that had made it through the appeals process of the lower courts and had come to the highest court in the province for a final decision. Thus the cases that were tried in the supreme court usually meant life or death for the accused.

Jesus identifies Pergamos as being the seat of Satan’s religion. Interestingly Pergamos has a long history with pagan cultic worship stretching as far back as Babylon. When the Persians overthrew Babylon a small contingent of Babylonian priests revolted against their new captors. They were defeated and fled to Asia Minor where they settled at Pergamos and set up a little training school there.

Here they continued to perpetuate Babylonian mysticism and became in essence the seat of Satanic worship. Babylonian religious belief centered around the idea that it formed a bridge between heaven and earth. The ruling monarch of Babylon became the head of the state religion, the concept of religion and politics being intertwined being a central feature of the Empire. One of the many titles the King of Babylon acquired was the title Pontifex Maximus which translated means The Greatest Bridge Builder.

For many years, under Persians, Greeks, and then during the Hellenistic period, Pergamos was a center for pagan Babylonian mysticism. When the Romans took over the city the cult was absorbed by Roman religion and in some ways influenced it.

Pergamos was known as a city of temples, one of the most important being the Temple of Zeus. Another important Greek deity that had a major temple at Pergamos was Aesculapius, considered the patron god of healing and symbolized by a serpent. In most cases, the temples of Aesculapius housed living serpents. Adjacent to the temple was a famous medical training school as well also dedicated to Aesculapius.

Pergamos also boasted a massive library and was considered an educational center. The Pergamon Library housed a collection of 200,000 books, rivaling even the great Egyptian library in Alexandria. When Egypt embargoed the export of paper to Pergamos, the city adapted by creating their own writing material made out of cured skins. The material was called parchment or

Today the most famous structure in the city is the monumental altar most likely dedicated to Zeus and Athena. The foundation can still be found in the upper city but the frieze which originally decorated the altar has been transferred to the Pergamon Museum in Berlin.

The ruins of the theatre of Pergamon, built during the Hellenistic period can still be found today along with temples to Dionysus and Athena. An agora, royal palaces, and Roman baths from the Roman period can also be found in the ruins.