The Old Uyghur script developed from writing traditions ultimately derived from the
Aramaic script through the intermediary of the
Sogdian script. Archaeological evidence indicates that early Turkic societies possessed at least two writing systems, one being the Old Uyghur alphabet, and the other being the
Turkic Runic script. Both stem from Sogdian models based on the Aramaic (and later Syriac) alphabet. Sogdian communities active along the Eurasian trade routes played an important role in transmitting literacy to Turkic populations, and Sogdian writing was already employed for official purposes in the
Turkic Khaganate in the late 6th century, as evidenced by the
Bugut inscription. A cursive form of the Sogdian script that developed in the late 7th or early 8th century was subsequently adapted for Turkic languages and became the basis of the Old Uyghur alphabet. The script became closely associated with the
Uyghurs, whose culture was strongly influenced by Sogdian merchants and religious communities. Variants of the script were employed for different religious traditions, including Buddhist, Manichaean, and Christian texts, reflecting broader patterns of script usage in medieval Central Asia. The Old Uyghur script was used extensively in the
West Uyghur kingdom between the mid-ninth and early thirteenth centuries, and during the period of Mongol rule over the region, between the thirteenth and fourteenth centuries. Documents containing the script have also been discovered at
Dunhuang and
Khara-Khoto, written by the inhabitants of the West Uighur kingdom and their descendants. Some documents might be dated as late as the seventeenth century. According to the 11th-century scholar
Mahmud al-Kashgari, the script was used for diplomatic correspondence between
Kashgar and China and likely also for everyday administrative affairs among non-Islamic Turkic groups. The use of the script appears to have been largely confined to the eastern Turkic regions before the 13th century. After the conversion of the
Kara-Khanid Khanate to Islam, the
Arabic script became the principal script for writing Turkic in Muslim lands west of the
Pamirs, as demonstrated by commercial documents and literary works such as the
Kutadgu Bilig. The script gained renewed political significance during the Mongol conquest led by
Genghis Khan. According to traditional accounts, after his
defeat of the Naiman in 1204 he captured an Uyghur official known in Chinese sources as
Tata-tonga, who was ordered to teach the Mongolian princes to write using the Uyghur script. Adapted for Mongolian, this writing system became the "Mongol Official Alphabet", which was essentially the Uyghur alphabet in administrative use. The Mongols carried this script westward across the Pamirs and established it as the official writing system in regions such as
Transoxiana and
Persia. Although it was initially used there to write Mongolian, it remained the official alphabet even after Turkish replaced Mongolian as the principal administrative language. As a result, the 15th-century Turkish manuscripts written in so-called "Uyghur script" were produced in this Mongol administrative alphabet, rather than in a continuous scribal tradition directly inherited from earlier Uyghur usage. No Uyghur-script texts dating to the period between the Turkic conversion to Islam and the Mongol conquest, that employ the earlier orthographic system with its elaborate dots and marks, have survived. In western parts of the Mongol domains the script survived primarily as a formal court script even after Turkic languages became the main administrative languages. By the 15th century its use had declined significantly, and manuscripts written in the script were sometimes accompanied by interlinear transcriptions in Arabic script to facilitate reading. One of the latest known examples is a proclamation issued by
Mehmed II following his victory over
Uzun Hasan in 1473, written in the Uyghur-derived script with an accompanying Arabic transcription. == Characteristics ==