The extent of the Persian empire was, in essentials, defined by the great conquests of Cyrus and Cambyses. Darius was no more a conquistador than Augustus. The task he set himself was to round off the empire and secure its borders: for this purpose in Asia Minor and Armenia he subdued the mountain-tribes and ad vanced the frontier as far as the Caucasus, Colchis alone remaining an independent kingdom under the imperial suzerainty. So, too, he annexed the Indus valley and the auriferous hill-country of Kafiristan and Cashmir or Herod. iii. 93, vii. 67, 96; Steph. Byz.), as well as the Dardae in Dardistan on the Indus (Ctesias, Ind. fr. 12. 70, etc.). From this point he directed several campaigns against the Amyrgian Sacae, on the Pamir Plateau and northwards, whom he enumerates in his list of subject races, and whose mounted archers formed a main division of the armies despatched against the Greeks. It was obviously an attempt to take the nomads of the Turanian steppe in the rear and to reduce them to quiescence, which led to his un fortunate expedition against the Scythians of the Russian steppes (c. 512 B.C. ; see DARIus).
Side by side with these wars, we can read, even in the scanty tradition at our disposal, a consistent effort to further the great civilizing mission imposed on the empire. In the district of Herat, Darius established a great water-basin, designed to facilitate the cultivation of the steppe (Herod. iii. ii7). He had the course of the river Indus explored by the Carian captain Scylax of Cary anda, who then navigated the Indian ocean back to Suez (Herod. iv. 44) and wrote an account of his voyage in Greek. The desire to create a direct communication between the seclusion of Persis and the commerce of the world is evident in his foundation of several harbours, described by Nearchus, on the Persian coast. But this design is still more patent in his completion of a great canal, already begun by Necho, from the Nile to Suez, along which several monuments of Darius have been preserved. Thus it was possible, as says the remnant of an hieroglyphic inscription there discovered, "for ships to sail direct from the Nile to Persia, over Saba." In the time of Herodotus the canal was in constant use (ii. i58, iv. 39) : afterwards, when Egypt regained her inde pendence, it decayed, till restored by the second Ptolemy. Even the circumnavigation of Africa was attempted under Xerxes (Herod. iv. 43) Religion and Art.—It has already been mentioned, that, in his efforts to conciliate the Egyptians, Darius placed his chief reliance on the priesthood : and the same tendency runs throughout the imperial policy towards the conquered races. Thus Cyrus himself gave the exiled Jews in Babylon permission to return and rebuild Jerusalem. Darius allowed the restoration of the Temple ; and Artaxerxes I., by the protection accorded to Ezra and Nehemiah, made the foundation of Judaism possible (see JEWS : §§i9 sqq.). Analogously in an edict, of which a later copy is preserved in an inscription (see p. 569), Darius commands Gadatas, the governor of a domain (rrapabEccros) in Magnesia on the Maeander, to ob serve scrupulously the privileges of the Apollo-sanctuary. With all the Greek oracles—even those in the mother-country—the Persians were on the best of terms. And since these might reason ably expect an enormous extension of their influence from the establishment of a Persian dominion, we find them all zealously mediatizing during the expedition of Xerxes.
For the development of the Asiatic religions, the Persian empire was of prime importance. The definite erection of a single, vast, world-empire cost them their original connection with the state, and compelled them in future to address themselves, not to the community at large, but to individuals, to promise, not political success nor the independence of the people, but the welfare of the man. Thus they became at once universal and capable of extension by propaganda ; and, with this, of entering into keen competition one with the other. These traits are most clearly marked in
Judaism ; but after the Achaemenid period, they are common to all Oriental creeds, though our information as to most is scanty in the extreme.
In this competition of religions that of Iran played a most spirited part. The Persian kings—none more so than Darius, whose religious convictions are enshrined in his inscriptions—and, with the kings, their people, were ardent professors of the pure doctrine of Zoroaster; and the Persians settled in the provinces diffused his creed throughout the whole empire. Thus a strong Persian propagandism arose especially in Armenia and Cappadocia, where the religion took deep root among the people, but also in Lydia and Lycia. In the process, however, important modifications were introduced. In contrast with Judaism, Zoroastrianism did not enter the lists against all gods save its own, but found no difficulty in recognizing them as subordinate powers—helpers and servants of Ahuramazda. Consequently, the foreign creeds often reacted upon the Persian. In Cappadocia, Aramaic inscriptions have been discovered (1900), in which the indigenous god, there termed Bel the king, recognizes the "Mazdayasnian Religion" (Din Maz dayasnish)—i.e., the religion of Ahuramazda personified as a woman—as his sister and wife (Lidzbarski, Ephem. f. semit. Epigr. i. 59 sqq•) The gorgeous cult of the gods of civilization (especially of Babylon), with their host of temples, images and festivals, ex ercised a corresponding influence on the mother-country. More over, the unadulterated doctrine of Zoroaster could no more be come a permanent popular religion than can Christianity. For the masses can make little of abstractions and an omnipotent, omni present deity; they need concrete divine powers, standing nearer to themselves and their lot. Thus the old figures of the Aryan folk-religion return to the foreground, there to be amalgamated with the Babylonian divinities. The goddess of springs and streams (of the Oxus in particular) and of all fertility—Ardvisura Anahita, Anaitis—is endowed with the form of the Babylonian Ishtar and Belit. She is now depicted as a beautiful and strong woman, with prominent breasts, a golden crown of stars and golden raiment. She is worshipped as the goddess of generation and all sexual life (cf. Herod. i. 131, where the names of Mithras and Anaitis are interchanged) ; and religious prostitution is trans ferred to her service (Strabo xi. 532, xii. 559). At her side stands the sun-god Mithras, who is represented as a young and vic torious hero. Both deities occupy the very first rank in the popular creed; while to the theologian they are the most potent of the good powers—Mithras being the herald and propagator of the service of Light and the mediator betwixt man and Ahuramazda, who now fades more into the background. Thus, in the subsequent period, the Persian religion appears purely as the religion of Mithras. The festival of Mithras is the chief festival of the empire, at which the king drinks and is drunken, and dances the national dance (Ctes. Jr. 55; Duris Jr. 13). This development culminated under Artaxerxes II., who, according to Berossus (fr. i6 op. Clem. Alex. Prot. i. 5, 65), first erected statues to Anaitis in Persepolis, Ecbatana, Bactria, Susa, Babylon, Damascus and Sardis. The truth of this account is proved by the fact that Artaxerxes II. and Artaxerxes III. are the only Achaemenids who, in their inscriptions, invoke Anaitis and Mithra side by side with Ahuramazda. Other gods, who come into prominence, are the dragon-slayer Verethraghna (Artagnes) and the Good Thought (Vohumano, Omanos) ; and even the Sacaean festival is adopted from Babylon (Berossus Jr. 3; Ctes. Jr. 16; Strabo xi. 512, etc.). The chief centres of the Persian cults in the west were the district of Acilisene in Armenia (Strabo xi. 532, etc.) the town of Zela in Cappadocia (Strabo xii. 559), and several cities in Lydia.