Since Seleucus' legitimate heir, Demetrius I Soter, was still a hostage in Rome, Antiochus, with the help of King Eumenes II of Pergamum, seized the throne for himself, proclaiming himself co-regent for another son of Seleucus, an infant named Antiochus (whom he then murdered a few years later).
Phaistos had its own currency and had created an alliance with other autonomous Cretan cities, and with the king of Pergamon Eumenes II.
Prior to a naval battle with King Eumenes II of Pergamon, Hannibal sent a herald with a message for the opposing commander.