Its mineral wealth was boundless.

It inherited the prestige of the Median, the Babylonian, the Assyrian, the Chaldean Empires, whose annals reached back through more than twenty centuries.
THE PERSIAN EMPIRE.

Persia had always looked upon European Greece as politically insignificant, for it had scarcely half the territorial extent of one of her satrapies.

Her expeditions for compelling its obedience had, however, taught her the military qualities of its people.
In her forces were incorporated Greek mercenaries, esteemed the very best of her troops.

She did not hesitate sometimes to give the command of her armies to Greek generals, of her fleets to Greek captains.