Besides the “Nordarisch” mentioned above which was written in Brahmi, three other Iranian languages have left literary remains in Central Asia, all written in an alphabet of Aramaic origin.  Two of them apparently represent the speech of south-western Persia under the Sassanids, and of north-western Persia under the Arsacids.  The texts preserved in both are Manichaean but the third Iranian language, or Sogdian, has a more varied literary content and offers Buddhist, Manichaean and Christian texts, apparently in that chronological order.  It was originally the language of the region round Samarkand but acquired an international character for it was used by merchants throughout the Tarim basin and spread even to China.  Some Christian texts in Syriac have also been found.

The Orkhon inscriptions exhibit an old Turkish dialect written in the characters commonly called Runes and this Runic alphabet is used in manuscripts found at Tun-huang and Miran but those hitherto published are not Buddhist.  But another Turkish dialect written in the Uigur alphabet, which is derived from the Syriac, was (like Sogdian) extensively used for Buddhist, Manichaean and Christian literature.  The name Uigur is perhaps more correctly applied to the alphabet than the language[466] which appears to have been the literary form of the various Turkish idioms spoken north and south of the Tien-shan.  The use of this dialect for Buddhist literature spread considerably when the Uigurs broke the power of Tibet in the Tarim basin about 860 and founded a kingdom themselves:  it extended into China and lasted long, for Sutras in Uigur were printed at Peking in 1330 and Uigur manuscripts copied in the reign of K’ang Hsi (1662-1723) are reported from a monastery near Suchow.[467] I am informed that a variety of this alphabet written in vertical columns is still used in some parts of Kansu where a Turkish dialect is spoken.  Though Turkish was used by Buddhists in both the east and west of the Tarim basin, it appears to have been introduced into Khotan only after the Moslim conquest.  Another Semitic script, hitherto unknown and found only in a fragmentary form, is believed to be the writing of the White Huns or Hephthalites.

As the Tibetans were the predominant power in the Tarim basin from at least the middle of the eighth until the middle of the ninth century, it is not surprising that great stores of Tibetan manuscripts have been found in the regions of Khotan, Miran and Tun-huang.  In Turfan, as lying more to the north, traces of Tibetan influence, though not absent, are fewer.  The documents discovered must be anterior to the ninth century and comprise numerous official and business papers as well as Buddhist translations.[468] They are of great importance for the history of the Tibetan language and also indicate that at the period when they were written Buddhism at most shared with the Bon religion the allegiance of the Tibetans.  No Manichaean or Christian translations in Tibetan have yet been discovered.