In the 6th
century BC the Achaemenian ruler Cyrus II the Great established his authority over the area. Darius I the Great
consolidated Achaemenian rule of the region through the provinces, or satrapies, of Aria (in the region of modern Herat), Bactria (Balkh), Sattagydia (Ghazni to the Indus River), Arachosia (Qandahar), and Drangiana (Seistan). Alexander the Great overthrew the Achaemenians and conquered most of the Afghan satrapies before he left for India in 327 BC. Ruins of an outpost Greek city founded about 325 BC were discovered at Ay Khanom, at the confluence of the Amu and Kowkcheh rivers. Excavations there produced inscriptions and transcriptions of Delphic precepts written in a script influenced by cursive Greek. Greek decorative elements dominate the architecture, including an immense administrative center, a theatre, and a gymnasium. A nomadic raid about 130 BC ended the Greek era at Ay Khanom.After Alexander's death in 323 BC, the eastern satrapies passed to the Seleucid
dynasty, which ruled from Babylon. In about 304 BC the territory south of the Hindu Kush was ceded to the Maurya dynasty of northern India. Bilingual rock inscriptions in Greek and Aramaic (the official language of the Achaemenians) found at Qandahar and Laghman (in eastern Afghanistan) date from the reign of Ashoka (c. 265-238 BC, or c. 273-232 BC), the Maurya dynasty's most renowned emperor. Diodotus, a local Greco-Bactrian governor, declared the Afghan plain of the Amu River independent about 250 BC; Greco-Bactrian conquerors moved south about 180 BC and established their rule at Kabul and in the Punjab. The Parthians of eastern Iran also broke away from the Seleucids, establishing control over Seistan and Qandahar in the south.
Kushan DYNASTYalso spelled KUSANA, ruling line descended from the Yüeh-chih (q.v.), a people that ruled over most of the northern Indian subcontinent, Afghanistan, and parts of Central Asia during the first three centuries of the Christian era. The Yüeh-chih conquered Bactria in the 2nd
century BC and divided the country into five chiefdoms, one of which was that of the Kushans (Kuei-shuang). A hundred years later, the Kushan chief Kujula Kadphises (Chiu-Chiu-Chueh) secured the political unification of the Yüeh-chih kingdom under himself. Under Kaniska I (fl. 1st century AD) and his successors, the Kushan kingdom reached its height. It was acknowledged as one of the four great Eurasian powers of its time (the others being China, Rome, and Parthia). The Kushans were instrumental in spreading Buddhism in Central Asia and China and in developing Mahayana Buddhism and the Gandhara and Mathura schools of art.The Kushans became affluent through trade, particularly with Rome, as their large issues of gold coins show. These coins, which exhibit the figures of Greek, Roman, Iranian, Hindu, and Buddhist deities and bear inscriptions in adapted Greek letters, are witness to the toleration and to the syncretism in religion and art that prevailed in the Kushan empire. After the rise of the Sasanian dynasty in Iran and of local powers in northern India, Kushan rule declined.The Kushan Empire did not long survive Kaniska, though for centuries Kushan princes continued to rule in various provinces. Persian Sasanians established control over parts of Afghanistan, including Bagram, in AD 241. In AD 400 a new wave of Central Asian nomads under the Hephthalites took control, only to be defeated in AD 565 by a coalition of Sasanians and Western Turks. From the 5th through the 7th century many Chinese Buddhist pilgrims continued to travel through Afghanistan. The pilgrim Hsüan-tsang (Xüanzang) wrote an important account of his travels, and several of the religious centres he visited, including Hadda, Ghazna, Konduz, Bamian, Shotorak, and Bagram, have been excavated.