Achaeus recovered all the districts which Attalus I had gained on the Seleucids once more, thereby destroying the aspirations of Attalus to become a major power, driving him back to the territory of Pergamum in 222 BC,[5] and taking the whole of Asia on the western side of the Taurus.

[6] In 218 BC, Attalus regained control over the Greek cities of northern Ionia, Aeolis and Troas and the Mysian lands as far east as the Megistos river,[7] which occupied Achaeus during the fourth Syrian war.

[8] Upon the conclusion of a treaty with Ptolemy IV of Egypt Antiochus crossed the Taurus in 216 BC, united his forces with Attalus, and in one campaign deprived Achaeus of his dominions and took Sardis (with the exception of the citadel).

After sustaining a siege of two years, the citadel at last fell into the hands of Antiochus in 214 BC, through the treachery of Bolis (who had been employed by Sosibius, minister to Ptolemy).

Bolis pledged to deliver Achaeus to safety, but turned him over to Antiochus, who immediately put him to death.