The Bactrian language
 
Group Iranian (with Persian, Kurdish etc.), Southeast Iranian (with Pamir languages, Khwaresmian, Pashto etc.)
Geography & History Bactrian is a Middle Iranian language which used to be spoken in Central Asia, in the region called Bactria or Tocharistan, along the upper Amudarya river. In the 1-3rd centuries Bactrian was the official language of the Kuchanian kingdom, and in the 5-6th centuries - of the Ephtalite kingdom. In the 11th century Arabic sources mention Iranian dialects of Central Asia which can be relics of Bactrian, which was assimilated by that time by Persian. 
Phonetics The phonetic system remains unclear, because not all the phonemes can be identified from written documents because of the peculiar script. Supposedly, there were 9 vowels (4 long and short parallels, and the short o), which were often subject to reduction. The consonant mutations included *d > l, *c > dj, -rs- > -s'- etc. In general, Bactrian phonetics has features both seen in modern Pashto and in Middle Iranian tongues like Parthian and Sogdian
Morphology In morphology, Bactrian went rather far from the ancient Iranian languages than other relative tongues. The gender disappeared, only 2 noun cases were preserved (direct and indirect), the ancient inflected forms of the past tense were replaced by analytical constructions. The language used a definite article i which acted as a relative pronoun as well.
Writing Aramaic alphabet (2nd century BC - 1st century AD), Greek alphabet (since the 2nd century)
Close Contacts Turkish tongues of Central Asia, the Middle Persian language.
Sample  
Picture Head of a Bactrian sovereign
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