By these means the actual burthen of taxation upon the subject was rendered to some extent uncertain and indefinite, and the benefits of the fixed tribute system were diminished.  But the chief drawback upon it has still to be mentioned.  While the claims of the crown upon its subjects were definite and could not be exceeded, the satrap was at liberty to make any exactions that he pleased beyond them.  There is every reason to believe that he received no stipend, and that, consequently, the burthen of supporting him, his body-guard, and his Court was intended to fall on the province which had the benefit of his superintendence.  Like a Roman proconsul, he was to pay himself out of the pockets of his subjects; and, like that class of persons, he took care to pay himself highly.  It has been calculated that one satrap of Babylon drew from his province annually in actual coin a sum equal to L100,000. of our money.  We can scarcely doubt that the claims made by the provincial governors were, on the average, at least equal to those of the crown; and they had the disadvantage of being irregular, uncertain, and purely arbitrary.

Thus, what was gained by the new system was not so much the relief of the subject from uncertain taxation as the advantage to the crown of knowing beforehand what the revenue would be, and being able to regulate its expenditure accordingly.  Still a certain amount of benefit did undoubtedly accrue to the provincials from the system; since it gave them the crown for their protector.  So long as the payments made to the state were irregular, it was, or at least seemed to be, for the interest of the crown to obtain from each province as much as it could anyhow pay.  When the state dues were once fixed, as the crown gained nothing by the rapacity of its officers, but rather lost, since the province became exhausted, it was interested in checking greed, and seeing that the provinces were administered by wise and good satraps.

The control of its great officers is always the main difficulty of a despotic government, when it is extended over a large space of territory and embraces many millions of men.  The system devised by Darius for checking and controlling his satraps was probably the best that has ever yet been brought into operation.  His plan was to establish in every province at least three officers holding their authority directly from the crown, and only responsible to it, who would therefore act as checks one upon another.  These were the satrap, the military commandant, and the secretary.  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