The growing power of Macedon, against which Demosthenes was at this time in vain warning the careless Athenians, attracted the consideration of Ochus or of his counsellors; and orders went forth from the Court that Persian influence was to be used to check and depress the rising kingdom.

A force was consequently despatched to assist the Thracian prince, Cersobleptes, to maintain his independence; and such effectual aid was given to the city of Perinthus that the numerous and well-appointed army with which Philip had commenced its siege was completely baffled and compelled to give up the attempt (B.C.
340).

The battle of Chseroneia had not yet been fought, and Macedonia was still but one of the many states which disputed for supremacy over Greece; but it is evident that she had already awakened the suspicions of Persia, which saw a rival and a possible assailant in the rapidly growing monarchy.
Greater and more systematic efforts might possibly have been made, and the power of Macedon might perhaps have been kept within bounds, had not the inveterate evil of conspiracy and revolution once more shown itself at the Court, and paralyzed for a time the action of the Empire on communities beyond its borders.

Ochus, while he was a vigorous ruler and administrator, was harsh and sanguinary.

His violence and cruelty rendered him hateful to his subjects; and it is not unlikely that they caused even those who stood highest in his favor to feel insecure.
Bagoas may have feared that sooner or later he would himself be one of the monarch's victims, and have been induced by a genuine alarm to remove the source of his terrors.