Persian conquests and the fact that the empire united dozens of peoples helped its subjects to broaden their intellectual and geographical horizons. The Achaemenid period was one of intensive ethnic mingling and syncretism in cultures and beliefs. The prime reason was that contacts between different parts of the empire had become more regular than in the previous period. More specifically, the sources report frequent visits by state functionaries from Arachosia, Haraiva, Gandh¯ara, Bactria and other eastern Iranian or Central Asian countries to Susa and Persepolis.
Iran, which had since time immemorial acted as an intermediary in East-West cultural exchange, maintained its historical role under the Achacmenids. At the same time, the Iranians created their own original and sophisticated civilization. One of its achievements was the adaptation of the cuneiform script for writing Old Persian. The chief official written language was Aramaic; under the Achaemenids, standard formulae were devised to render Aramaic terms and clerical expressions into the different Iranian languages; and from the official written Aramaic of the Achaemenids, the later written forms of Parthian, Middle Persian, Sogdian and Chorasmian were derived. It was in this period that the peoples of Central Asia first became acquainted with Aramaic script. This, too, was the period when a number of Old Iranian words – chiefly socio-economic, military and administrative terms – were borrowed by Indian languages.
Among the outstanding achievements of Old Iranian civilization was Achaemenid art, which is known above all from the monuments of Pasargadac, Persepolis and Susa, the Bisutun rock reliefs, the Persian royal tombs at Naqsh-i Rustam, and from large quantities of metal and stone carvings. The subjects may be military triumphs or hunting exploits by Persian kings and warriors, combat between heroic monarchs and various monsters symbolizing vil, or palace and religious rituals. It was the characteristics of this art that took shape at the turn of the sixth and fifth centuries b.c.
History of Civilizations of Central Asia Volume II: The Development of Sedentary and Nomadic Civilizations: 700 B.C. to A.D. 250