Successor of: Attalus I Soter
- Father: Attalus I Soter
- Mother: Apollonis of Cyzicus
- Wife: Stratonice IV, daughter of Ariarathes IV of Cappadocia
- Son: Attalus III Philometor
- Born before 220.
- 197: His father Attalus I Soter suffers a stroke and makes Eumenes co-ruler; he becomes king in the same year and inherits a policy in which he presents himself as protector of Greece. He also inherits an alliance with Rome.
- 194: Refuses an alliance with Antiochus III the Great of the Seleucid Empire, and instead provokes the Syrian War, in which he is supported by Rome.
- 192: Attalus II Philadelphus visits Rome and warns against Antiochus III.
- 189: Battle of Magnesia: Antiochus defeated by the Romans and Pergamenes; Manlius Vulso attacks the Galatians.
- 188: Peace of Apamea: Rome awards Pergamon large parts of Asia Minor, including Ephesus, Telmessus, and Tralles.
- 183: War against king Prusias I of Bithynia; although Eumenes is defeated, Roman support gives him in the end victory.
- 183: Alliance with the towns of Crete.
- 182-179: War against king Pharnaces of Pontus; territorial gains.
- 175: Enables the succession of Antiochus IV Epiphanes in the Seleucid Empire.
- 172: During a visit to Rome, Eumenes, hostile to the Macedonian king Perseus, informs the Senate about Perseus' presumed plans to gain influence in Greece.
- On his return, Eumenes is attacked near Cirrha, and believed to be death. His brother Attalus becomes king and marries to queen Stratonice. When Eumenes returns, Attalus cedes power; Stratonice returns to her husband
- 171-168: Rome's Third Macedonian War. No Pergamene successes, and Eumenes is suspected by the Senate. After Rome's victory, the Senate refuses Eumenes' apology.
- Eumenes defeats the Galatians (Pergamon Altar), whom the Romans force him to leave autonomous (166).
- 159: Death; he is succeeded by his loyal brother, who remarries queen Stratonice
Succeeded by: Attalus II Philadelphus