Notwithstanding the close relations of Rome with the court of Alexandria and her royal ward, the senate by no means intended to be in reality, what it was in name, his "protector;" firmly resolved to give itself no concern about Asiatic affairs except in case of extreme necessity, and to limit the sphere of the Roman power by the Pillars of Hercules and the Hellespont, it allowed the great-king to take his course.

He himself was not probably in earnest with the conquest of Egypt proper--which was more easily talked of than achieved--but he contemplated the subjugation of the foreign possessions of Egypt one after another, and at once attacked those in Cilicia as well as in Syria and Palestine.
The great victory, which he gained in 556 over the Egyptian general Scopas at Mount Panium near the sources of the Jordan, not only gave him complete possession of that region as far as the frontier of Egypt proper, but so alarmed the Egyptian guardians of the young king that, to prevent Antiochus from invading Egypt, they submitted to a peace and sealed it by the betrothal of their ward to Cleopatra the daughter of Antiochus.

When he had thus achieved his first object, he proceeded in the following year, that of the battle of Cynoscephalae, with a strong fleet of 100 decked and 100 open vessels to Asia Minor, to take possession of the districts that formerly belonged to Egypt on the south and west coasts of Asia Minor--probably the Egyptian government had ceded these districts, which were -de facto- in the hands of Philip, to Antiochus under the peace, and had renounced all their foreign possessions in his favour--and to recover the Greeks of Asia Minor generally for his empire.

At the same time a strong Syrian land-army assembled in Sardes.
Difficulties with Rome This enterprise had an indirect bearing on the Romans who from the first had laid it down as a condition for Philip that he should withdraw his garrisons from Asia Minor and should leave to the Rhodians and Pergamenes their territory and to the free cities their former constitution unimpaired, and who had now to look on while Antiochus took possession of them in Philip's place.

Attalus and the Rhodians found themselves now directly threatened by Antiochus with precisely the same danger as had driven them a few years before into the war with Philip; and they naturally sought to involve the Romans in this war as well as in that which had just terminated.