The satrap was charged with the civil administration, and especially with the department of finance.

The commandant was supreme over the troops.

The office of the secretary is less clearly defined; but it probably consisted mainly in keeping the Court informed by despatches of all that went on in the province.

Thus, if the satrap were inclined to revolt, he had, in the first place, to persuade the commandant, who would naturally think that, if he ran the risk, it might as well be for himself; and, further, he had to escape the lynx eyes of the secretary, whose general right of superintendence gave him entrance everywhere, and whose prospects of advancement would probably depend a good deal upon the diligence and success with which he discharged the office of "King's Eye" and "Ear." So, if the commandant were ambitious of independent sway, he must persuade the satrap, or he would have no money to pay his troops; and he too must blind the secretary, or else bribe him into silence.

As for the secretary, having neither men nor money at his command, it was impossible that he should think of rebellion.
But the precautions taken against revolt did not end here.