Founding of the Kingdom of Pergamon

In 282 BC, Philetaerus, an officer who had been entrusted by Lysimachus with guarding a treasure of 9,000 talents in the hilltop fortress of Pergamon in western Anatolia, switched his loyalty to Seleucus and began to rule the city himself. His successors, known as the Attalid dynasty, built this base into an independent kingdom. His nephew Eumenes I broke away from the Seleucids, and Attalus I became the first of the family to take the title of king after defeating the Gauls, who had settled in Anatolia, around 238 BC. Pergamon became one of the most brilliant cities of the Hellenistic world. Its rulers built a spectacular acropolis with temples, a steep theatre and the Great Altar, whose sculptures are now in Berlin. They also founded a great library that rivaled Alexandria's. The Attalids allied with Rome against Macedon and the Seleucids and were rewarded with large territories. In 133 BC, the last king, Attalus III, died without an heir and left his entire kingdom to Rome, which made it the Roman province of Asia.