282 BC to 133 BC
Asia Minor or AnatoliaThe Attalid dynasty or the Kingdom of Pergamon was a Hellenistic Greek dynasty that ruled much of Asia Minor, from the city of Pergamon, after the death of Lysimachus, a general of Alexander the Great.
In 282 BC, Philetaerus deserted Lysimachus, offering himself and the important fortress of Pergamon, along with its treasury, to Seleucus I Nicator, who defeated and killed Lysimachus at the Battle of Corupedium in 281 BC. Seleucus was killed a few months later.
Philetaerus, especially after the death of Seleucus, enjoyed considerable autonomy despite being nominally under the Seleucids. He acquired considerable wealth because Pergamon had been the treasure-hold of Lysimachus and extended his power and influence beyond Pergamon. He contributed troops, money, and food to the city of Cyzicus, in Mysia, for its defense against the invading Gauls, thus gaining prestige and goodwill for him and his family.
Pausanias wrote that the greatest achievement of Attalus I (r. 241–197 BC) was his defeat of the Gauls, by which he meant the Galatians, Celts who had migrated to central Asia Minor and established themselves as a major military power.
Achaeus assumed control of the army. Antiochus III the Great then made him governor of Seleucid territories north of the Taurus. Within two years he recovered the lost territories and forced Attalus within the walls of Pergamon. However, he was accused of intending to revolt, and to protect himself he proclaimed himself king.
In 188 BC, after the war against the Seleucids, the Romans seized the possessions of the defeated Antiochus III the Great in Asia Minor and gave Mysia, Lydia, Phrygia, and Pamphylia to the kingdom of Pergamon and Caria Lycia and Pisidia, in the southwestern corner of Asia Minor, to Rhodes, another Roman ally. Later the Romans gave these possessions of Rhodes to Pergamon.
The Romans were reluctant to take on territory in Asia Minor and did not take charge of the kingdom. Aristonicus claimed to be the illegitimate son of Eumenes II, assumed the dynastic name of Eumenes III, claimed the throne, instigated a rebellion, and in 132 BC "occupied Asia, which had been bequested to the Roman people and was supposed to be free".