The government by satraps, which was then complete, was common to Persia with other despotic empires; but as it entailed a multitude of abuses, attempts were made as much as possible to mitigate them.
The advantage which, in this particular, the Persian system of administration possessed over all others of the same kind, was the careful separation made between the civil and military powers; the exceptions which occurred in the latter ages of the empire having grown out of abuses. According to Persian ideas the king had a twofold duty to perform, of providing for the security and also for the good government and cultivation, of his empire: to secure the former object, garrisons were established throughout its whole extent; and the civil authorities were appointed to provide for the latter.
The foundation of this beneficial arrangement was laid at the very commencement of the empire, by the appointment of receivers of the royal treasury, together with that of commanders of the forces, and the same continued after the provinces came to be more accurately divided, and satraps to be created. Xenophon gives us the most satisfactory proof of this, when he records the first nomination and appointment of satraps, which, as he tells us, were first made by Cyrus.
“You know,” he is introduced saying to his friends, “that I have left garrisons and their commandants in the conquered countries and cities, to whom I have given in charge to attend to nothing else but their security. Together with these I shall also appoint satraps who may govern the inhabitants, receive the tribute, pay the garrisons, and attend to all other necessary points of business.” This institution continued uninterrupted for a long period, and the satraps are repeatedly mentioned in history together with the commandants of troops. However, in the later ages of the Persian monarchy, it became the custom to appoint the satraps to the command also of the king’s troops, more especially when they happened to be individuals of the royal family. In this manner the younger Cyrus was satrap of Mysia, Phrygia, and Lydia, and at the same time generalissimo of all the forces assembled in the plain of Castolus. The same we find to have been the case with Pharnabazus and others, so much so, that even in the time of Xenophon it had become customary for the satrap of a province to be also commander of the forces there; more especially in the frontier provinces, where such a union of powers was more especially necessary. The pernicious effects of this practice, and its tendency to promote revolt among the satraps, and to prepare the way for the internal dissolution of the empire, are sufficiently proved by the single example of the younger Cyrus. Notwithstanding, however, this abuse, it is not true that a military government was introduced in the provinces, for the other civil officers continued to be independent of the commanders of the forces, and the latter were not allowed to take any part in the civil administration. Xenophon tells us that the satraps were entrusted with the surveillance of the commanders of the troops as well as over the civil magistrates; the king of Persia appointing persons of both descriptions commanders of the forces, and also magistrates to govern the country, the one class being bound to pay deference to the other.