The Kushano-Sasanian kingdom in Bactria

Early in his reign, according to al-Tabari, Ardashir I marched from Fars through Sistan, Gurgan and Abarshahr to Merv, Balkh and Khwarezm and received envoys of the kings of the Kushans, of Turan and of Makran bringing their submission. This was perhaps only a formal submission: the Kushan lands became a Sasanian dominion under his son Shapur I, who by about 262 counted “Kushanshahr as far as Peshawar” among his provinces, while the Kushan dynasty lived on in its Indian territories. Coins of Bahram I (273–276) struck at Balkh suggest that at first the region was ruled directly.

The title Kushanshah is first securely attested in the Paikuli inscription of Narseh (about 293), where a Kushanshah heads the list of the king’s allies. The Kushanshahs bore Sasanian names — Ardashir, Peroz, Hormizd, Bahram (Warahran) — and probably came from a side branch of the royal house. Their gold coins from Balkh followed the late Kushan type, with the king sacrificing at an altar and the god Oesho with his bull, but showed the ruler in Sasanian crowns and bore Bactrian legends reading “great king of the Kushans”; other mints worked at Merv, at Herat and in Gandhara, and one Hormizd Kushanshah even called himself “king of kings of the Kushans”. They styled themselves “Mazda-worshipping lord”, yet kept Oesho — Vayu in the form of Shiva — on their coins, and surveys of eastern Bactria show no decline in settlement or irrigation in this period.

The chronology is disputed. Reference works give about 230–365, but numismatists date the beginning of Kushano-Sasanian coinage anywhere from 233 (J. Cribb) to the 350s (R. Göbl), and N. Schindel places its main series no earlier than about 300. The end came with the nomadic invasions of the mid-4th century: in 356 Shapur II had to winter among the Chionites and the Euseni (probably Kushans), and from 368 Armenian sources speak of a “king of the Kushans” at Balkh who repeatedly defeated the Persians — by then a ruler no longer subject to them.