The Byzantines took similar measures, sending envoys asking for help to Attalus and Achaeus.
Attalus was heartily disposed to help, but his support at this time was of very little weight, as he had been confined within the limits of his ancestral dominions by Achaeus.
But Achaeus, who was now master of all the country on this side of the Taurus and had recently assumed the royal title, promised his aid, and his decision to do so greatly raised the hopes of the Byzantines, while on the contrary, it alarmed Prusias and the Rhodians.
Achaeus was a relative of that Antiochus who had just succeeded to the throne of <a class="linkToPlace" target="_blank" href="/place?placename=Syria&groupId=995&placeId=502">Syria</a> and had acquired the dominion I stated by the following means.
When on the death of Seleucus, father of this Antiochus, his eldest son Seleucus succeeded him, Achaeus in his quality of a kinsman accompanied the king on his expedition across the Taurus about two years before the time I am speak of. For the young Seleucus, immediately on ascending the throne, having learnt that Attalus had appropriated all his dominions on this side of the Taurus hastened there to defend his interests.
He crossed the Taurus at the head of a great army, but perished assassinated by the <a class="linkToPlace" target="_blank" href="/place?placename=Gaul&groupId=598&placeId=1108">Gaul</a> Apaturius and Nicanor.
Achaeus, as his kinsman, at once avenged his murder by putting Nicanor and Apaturius to death, and taking the command of the army and the direction of affairs in his hands, conducted both with prudence and magnanimity.
For though the opportunity was favourable and he was eagerly urged by the troops to assume the diadem, he decided not to do so, and holding the throne for the younger brother Antiochus, advanced energetically and recovered the whole of the country on this side of Taurus. But when he met with a success that surpassed his expectations, having shut up Attalus in Pergamus itself and made himself master of all the rest of the country he was so elated by his good fortune that in a very short space of time he swerved clean away from rectitude, and having assumed the diadem and styled himself king he was at this moment the most imposing and formidable of all the kings and potentates on this side of the Taurus.
This was the man on whom the Byzantines most relied when they undertook the war against <a class="linkToPlace" target="_blank" href="/place?placename=Rhodes&groupId=931&placeId=1665">Rhodes</a> and Prusias.
Walbank Commentary