Bactrian language

Bactrian (Bactrian: Αριαο, romanized: ariao [arjaː], meaning "Iranian") was an Eastern Iranian language formerly spoken in the Central Asian region of Bactria (present-day Afghanistan) and used as the official language of the Kushan and the Hephthalite empires.

It was long thought that Avestan represented "Old Bactrian", but this notion had "rightly fallen into discredit by the end of the 19th century".

Bactrian, which was written predominantly in an alphabet based on the Greek script, was known natively as αριαο [arjaː] ("Arya"; an endonym common amongst Indo-Iranian peoples). It has also been known by names such as Greco-Bactrian or Kushan or Kushano-Bactrian.

Under Kushan rule, Bactria became known as Tukhara or Tokhara, and later as Tokharistan. When texts in two extinct and previously unknown Indo-European languages were discovered in the Tarim Basin of China, during the early 20th century, they were linked circumstantially to Tokharistan, and Bactrian was sometimes referred to as "Eteo-Tocharian" (i.e. "true" or "original" Tocharian). By the 1970s, however, it became clear that there was little evidence for such a connection. For instance, the Tarim "Tocharian" languages were "centum" languages within the Indo-European family, whereas Bactrian was an Iranian, thus "satem" language.

Bactrian is a part of the Eastern Iranian languages and shares features with the extinct Middle Iranian languages Sogdian and Khwarezmian (Eastern) and Parthian (Western), as well as sharing affinity with the modern Eastern Iranian languages such as Pashto and the Pamir subgroup of languages like Munji and Yidgha which are part of the same branch of the Pamir languages. Its genealogical position is unclear. According to another source, the present-day speakers of Munji, the modern Eastern Iranian language of the Munjan Valley in the Kuran wa Munjan district of the Badakhshan province in northeast Afghanistan, display the closest possible linguistic affinity with the Bactrian language.

Bactrian became the lingua franca of the Kushan Empire and the region of Bactria, replacing the Greek language. Bactrian was used by successive rulers in Bactria, until the arrival of the Umayyad Caliphate.

Following the conquest of Bactria by Alexander the Great in 323 BC, for about two centuries Greek was the administrative language of his Hellenistic successors, that is, the Seleucid and the Greco-Bactrian kingdoms. Eastern Scythian tribes (the Saka, or Sacaraucae of Greek sources) invaded the territory around 140 BC, and at some time after 124 BC, Bactria was overrun by a confederation of tribes belonging to the Great Yuezhi and Tokhari. In the 1st century AD, the Kushana, one of the Yuezhi tribes, founded the ruling dynasty of the Kushan Empire.

The Kushan Empire initially retained the Greek language for administrative purposes but soon began to use Bactrian. The Bactrian Rabatak inscription (discovered in 1993 and deciphered in 2000) records that the Kushan king Kanishka (c. 127 AD) discarded Greek ("Ionian") as the language of administration and adopted Bactrian ("Arya language"). The Greek language accordingly vanished from official use and only Bactrian was later attested. The Greek script, however, remained and was used to write Bactrian. The territorial expansion of the Kushans helped propagate Bactrian in other parts of Central Asia and South Western Asia.