The duty of the satraps was as yet but civil and financial: they were responsible for the imposts, they executed the royal decrees.

Their institution was outwardly designed but for the better collection of the revenue; but when from the ranks of the nobles Darius rose to the throne, he felt the advantage of creating subject principalities, calculated at once to remove and to content the more powerful and ambitious of his former equals.

Save Darius himself, no monarch in the known world possessed the dominion or enjoyed the splendour accorded to these imperial viceroys.

Babylon and Assyria fell to one--Media was not sufficient for another--nation was added to nation, and race to race, to form a province worthy the nomination of a representative of the great king.
His pomp and state were such as befitted the viceroy over monarchs.

A measure of silver, exceeding the Attic medimnus, was presented every day to the satrap of Babylon [43].