Bactrian Language

The Bactrian language is an extinct Eastern Iranian language which was spoken in the Central Asian region of Bactria. Linguistically, it is classified as belonging to the middle period of the East Iranian branch. Bactrian was closely related to the medieval Middle Iranian languages Sogdian, Khwarezmian and Parthian and shared similarities with the modern Eastern Iranian languages Pashto, Yidgha, and Munji.

Because Bactrian was written predominantly with the Greek alphabet, Bactrian is sometimes referred to as "Greco-Bactrian", "Kushan" or "Kushano-Bactrian". In medieval times, Bactria was also known as Tocharistan, after the incoming Tokharoi tribes, and until the 1970s Bactrian was sometimes referred to as 'Eteo-Tocharian', but it is now certain that Bactrian is not closely related to the Tocharian languages, which do not belong to the Iranian language group. An older notion that the language of the Avesta represented (Old) Bactrian "had rightly fallen into discredit by the end of the 19th century" (Gershevitch 1983, p. 1250).

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. At some time after 124 BC, Bactria was overrun by Yuezhi (Tokharoi) tribes. Subsequently, one of the tribes advanced to found the Kushan dynasty in the 1st century AD.

The Kushans at first retained the Greek language for administrative purposes, but soon began to use Bactrian, which however was then written using the Greek alphabet. The Bactrian Rabatak inscription (discovered in 1993 and deciphered in 2000) records that the Kushan king Kanishka (c. 127 AD) discarded Greek and adopted Bactrian as "his speech", and the Greek language accordingly vanishes from official use and only Bactrian is attested. The use of the Greek alphabet however remained.

In the 3rd century, the Kushan territories west of the Indus river fell to the Sassanids, and Bactrian began to be superseded by Middle Persian as the language of administration and trade. Next to Pahlavi script and (occasionally) Brahmi script, some coinage of this period is still in Greco-Bactrian script, but southwest Iranian vocabulary and phrasing supersedes Bactrian. Beginning in the mid-4th century, Bactria and northwestern India yielded to Hunnish tribes, and among these the Hephthalites prevailed. The Hunnish period is marked by linguistic diversity and in addition to Bactrian and Middle Persian, North Indic, Turkish and Latin vocabulary is also attested. The Hephthalites ruled their territories until the 7th century when they were overrun by the Arabs, after which the official use of Bactrian ceased. Although Bactrian briefly survived in other usage, that too eventually ceased, and the youngest examples of the language date to about the 9th century.

The territorial expansion of the Kushans helped propagate Bactrian to Northern India and parts of Central Asia. Sites at which Bactrian language inscriptions have been found are (in North-South order) Afrasiab in Uzbekistan, Kara-Tepe, Airtam, Delbarjin, Balkh, Kunduz, Baglan, Ratabak/Surkh Kotal, Oruzgan, Kabul, Dasht-e Navur, Ghazni, Jagatu in Afghanistan, as well as Islamabad, Shatial Bridge and Tochi Valley in Pakistan. Of eight known manuscript fragments in Greco-Bactrian script, one is from Lou-lan and seven from Toyoq, where they were discovered by the second and third Turpan expeditions under Albert von Le Coq. One of these may be a Buddhist text. One other manuscript, in Manichean script, was found at Qočo by Mary Boyce in 1958.

Among Iranian languages, the use of the Greek alphabet is unique to Bactrian. The Greek alphabet is however not ideal for representing Iranian languages. Although ambiguities remain, some of the disadvantages were overcome by using heta (Ͱ, ͱ) for /h/ and by introducing sho (Ϸ, ϸ) to represent /ʃ/. Xi (Ξ, ξ) and psi (Ψ, ψ) were not used for writing Bactrian as the ks and ps sequences do not occur in Bactrian. They were however probably used to represent numbers (just as other Greek letters were).