Moreover, the personal character of the second Antiochus must be taken into account. The vanity and impiety, which could accept the name of “Theus” for a service that fifty other Greeks had rendered to oppressed towns without regarding themselves as having done anything very remarkable, would alone indicate a weak and contemptible morale, and might justify us, did we know no more, in regarding the calamities of his reign as the fruit of his own unfitness to rule an empire. But there is sufficient evidence that he had other, and worse, vices. He was noted, even among Asiatic sovereigns, for luxury and debauchery; he neglected all state affairs in the pursuit of pleasure; his wives and male favorites were allowed to rule his kingdom at their will; and their most flagrant crimes were neither restrained nor punished. Such a character could have inspired neither respect nor fear. The satraps, to whom the conduct of their sovereign could not but become known, would be partly encouraged to follow the bad example, partly provoked by it to shake themselves free of so hateful and yet contemptible a master.
It was, probably, about the year B.C. 256, the fifth of the second Antiochus, when that prince, hard pressed by Philadelphus in the west, was also, perhaps, engaged in a war with the king of Atropatene in the north, that the standard of revolt was first actually raised in the eastern provinces, and a Syrian satrap ventured to declare himself an independent sovereign. This was Diodotus, satrap of Bactria a Greek, as his name shows. Suddenly assuming the state and style of king he issued coins stamped with his own name, and established himself without difficulty as sovereign over the large and flourishing province of Bactria, or the tract of fertile land about the upper and middle Oxus. This district had from a remote antiquity been one with special pretensions. The country was fertile, and much of it strong; the people were hardy and valiant; they were generally treated with exceptional favor by the Persian monarchs; and they seem to have had traditions which assigned them a pre-eminence among the Arian tribes at some indefinitely distant period. We may presume that they would gladly support the bold enterprise of their new monarch; they would feel their vanity flattered by the establishment of an independent Bactria, even though it were under Greek kings; and they would energetically second him in an enterprise which gratified their pride, while it held out to them hopes of a career of conquest, with its concomitants of plunder and glory. The settled quiet which they had enjoyed under the Achaemenide and the Seleucidae was probably not much to their taste; and they would gladly exchange so tame and dull a life for the pleasures of independence and the chances of empire.