Sogdian

The traditional Mongolian script was born of conquest and adapted for scripture. The standard account places its adoption around 1204, when Genghis Khan defeated the Naiman and took into service the Uyghur scribe Tata-tonga, who taught the Uyghur alphabet to the Mongol court for the writing of decrees. The Uyghur script itself descended from Sogdian and ultimately from Aramaic, and the Mongols inherited its most distinctive habit turned through ninety degrees: the script runs in vertical columns from top to bottom, the columns proceeding left to right, a direction no other major living script uses.

Letters take initial, medial and final forms, and the early orthography fit Mongolian only roughly, which later reformers addressed with added diacritics and refined letterforms. The script wrote the chancery documents of the largest land empire in history, and the Secret History of the Mongols, though preserved in Chinese transcription, was composed in this written tradition. Kublai Khan commissioned the square Phags-pa script to replace it, but the vertical letters outlived the experiment and remained the Mongols' own writing, carried by the Oirat in a refined clear script offshoot and by the Manchus, who adapted it for their own imperial language.

Before it was an Islamic city, Samarkand was the chief town of Sogdiana, whose merchants ran the trade between China and Iran and whose language was the working tongue of the eastern Silk Road. Sogdian religion grew from the same root as Zoroastrianism and diverged from it: the dead were exposed and their cleaned bones placed in decorated stone or ceramic ossuaries, of which many have been found around the city, and the goddess Nana, inherited from Mesopotamia, held a prominence she does not have in the Iranian tradition. Wall paintings uncovered at Afrasiab, the old mound, show ambassadors, processions and a rider on a camel, and are among the best evidence for how such a city saw itself in the seventh century.

Because Sogdians moved, so did their religions and other people's. Manichaean communities were established along the route to China, and Manichaean texts in Sogdian have been recovered from the oases to the east. The Church of the East had bishops in Central Asia and its Syriac liturgical books were copied in Sogdian too. Buddhist monasteries operated in the region and Sogdian translators carried texts into Chinese.

The Arab conquest under Qutayba ibn Muslim in 712 ended the Sogdian principalities. Conversion took generations rather than years, and the resulting city was Muslim, Persian speaking and, within two centuries, one of the intellectual centres of the eastern Islamic world.

The main source is a stele at Karabalgasun, the Uyghur capital in the Orkhon valley, inscribed in three languages: Chinese, Sogdian and Old Turkic. All three faces are damaged and no single face preserves the whole account, so the conversion has to be reconstructed by fitting fragments together. The Chinese face is the best preserved and presents the change as the khagan being instructed by teachers of the religion of light; the Sogdian face supplies detail the Chinese does not.

Chinese dynastic histories add an outside view and they are not friendly. The Tang record notes the Manichaean temples permitted in Chinese cities at Uyghur insistence and treats them as a concession extracted by a difficult ally, and it associates the religion with Sogdian merchants whose dealings the court resented.

Bogu Khagan was killed in 779 by his cousin Tun Bagha Tarkan, in a coup the Chinese sources connect to a plan to invade China that the Uyghur nobility did not want. Manichaeism survived the man who imposed it, which is the strongest evidence that it had taken root beyond the court, and later khagans went on patronising it. Reconstructing the episode means reading a damaged trilingual monument, a hostile foreign chronicle and later religious manuscripts from Turfan against one another, which is the ordinary condition of steppe religious history rather than a special difficulty here.