The eldest son of king
Attalus I and queen Apollonis, Eumenes was presumably born prior to 220 BC and was the eldest of four sons to Attalus I. Eumenes followed in his father's footsteps upon becoming king and collaborated with the
Romans to oppose first
Macedonian, then
Seleucid expansion towards the Aegean, leading to the defeat of
Antiochus the Great at the
Battle of Magnesia in 190 BC. He had refused to marry a daughter of
Antiochus III upon noticing that he was about to engage in a war against the Romans. He then had married
Stratonice of Pergamon, daughter of
Ariarathes IV (King of
Cappadocia) and his wife Antiochis, and their son was named
Attalus III.
Expansion of the kingdom after the Treaty of Apamea, with the gains of Pergamon (light blue) and
Rhodes (light green) Eumenes had followed his father's footsteps and aided the Romans whenever he could, firstly in the
Syrian War, where he both informed them by sending his brother
Attalus II and sided with the Romans, successfully aiding Rome in defeating Antiochus III in the
Battle of Magnesia. He then aided the Romans in the
War against Nabis where he aided both the
Aetolian and
Achaean leagues to defeat the Spartan tyrant
Nabis, and lastly in the
Third Macedonian War where he aided the Romans in defeating the Macedonian and Thracian army in the
Battle of Pydna against
Perseus of Macedon. He was then at war with the
Bithynian king
Prusias I in 183 BC, although being defeated, he received Roman support which ended in his victory. Following the
Peace of Apamea in 188 BC, he received the regions of
Phrygia,
Lydia,
Pisidia,
Pamphylia, and parts of
Lycia from his Roman allies. By dividing Asia Minor between their allies
Rhodes and Pergamon, the Romans made sure that neither state would be able to become too powerful in the region.
Falling out of favour with the Romans Eumenes later fell out of favour with the Romans after they suspected him of conspiring with
Perseus of Macedon. In order to avert suspicion, he sent his congratulations to Rome by his brother
Attalus II after the defeat of Perseus. Attalus was received courteously, and in 167 BC the Romans made an abortive attempt to install Attalus on the Pergamene throne. Eumenes in alarm set out to visit Rome in person to plead his case, but on his arrival at Brundusium (
Brindisi) was ordered to leave Italy at once. In the event, the ties of kinship proved strong, and Eumenes remained as ruler. He also warred with
Pharnaces I, who attempted to enlist the aid of the Seleucids, under
Seleucus IV but due to the peace of Apamea, denied siding with him. Later on, in around 179 BC, after suffering losses, Pharnaces sued for peace. When Eumenes' health began to weaken, his brother Attalus II ascended to the throne as a co-ruler in 160 BC. Since Eumenes' and Stratonice's son was still a minor, the throne was assumed by Attalus, who also married Stratonice in 158 BC upon becoming king. ==Legacy==