|Native to||Uyghur Khaganate, Qocho, Ganzhou Uyghur Kingdom|
|Region||Mongolia, Hami, Turpan, Gansu|
|Old Turkic script, Old Uyghur alphabet|
The Old Uyghur language evolved from Old Turkic after the Uyghur Khaganate broke up and remnants of it migrated to Turfan, Qomul (later Hami) and Gansu in the 9th century. The Uyghurs in Turfan and Qomul founded Qocho and adopted Manichaeism and Buddhism as their religions, while those in Gansu first founded the Ganzhou Uyghur Kingdom and became subjects of the Western Xia; and their descendants are the Yugur.
The Kingdom of Qocho survived as a client state of the Mongol Empire but was conquered by the Muslim Chagatai Khanate which conquered Turfan and Qomul and Islamisized the region. The Old Uyghur language then became extinct in Turfan and Qomul.
The modern Uyghur language is not descended from Old Uyghur; rather, it is a descendant of the Karluk languages spoken by the Kara-Khanid Khanate, in particular the Xākānī language described by Mahmud al-Kashgari while Western Yugur is considered to be the true descendant of Old Uyghur and is also called "Neo-Uygur" according to Gerard Clauson.
According to Frederik Coene and Martina Roos, Modern Uyghur and Western Yugur belong to entirely different branches of the Turkic language family, respectively southeastern (Karluk) and northeastern (Siberian Turkic).
Much of Old Uyghur literature is religious texts regarding Manichaeism and Buddhism, with examples found among the Dunhuang manuscripts. Multilingual inscriptions including Old Uyghur can be found at the Cloud Platform at Juyong Pass and the Stele of Sulaiman.
Qocho, the Uyghur kingdom created in 843, originally used the "runic" Old Turkic alphabet with a "anïγ" dialect. The Old Uyghur alphabet was adopted from local inhabitants, along with a "ayïγ" dialect, when they migrated into Turfan after 840.
- Marcel Erdal (1991). Old Turkic Word Formation: A Functional Approach to the Lexicon. Otto Harrassowitz Verlag. pp. 5–. ISBN 978-3-447-03084-7.
- Arik 2008, p. 145
- Clauson 1965, p. 57.
- Coene 2009, p. 75.
- Roos, Martina Erica. 2000. The Western Yugur (Yellow Yugur) Language: Grammar, Texts, Vocabulary. Diss. University of Leiden. Leiden, page 5.
- Chen et al, 1985
- "西域、 敦煌文献所见回鹊之佛经翻译". Archived from the original (PDF) on 2020-05-19. Retrieved 2015-09-07.
- Sinor, D. (1998), "Chapter 13 - Language situation and scripts", in Asimov, M.S.; Bosworth, C.E. (eds.), History of Civilisations of Central Asia, vol. 4 part II, UNESCO Publishing, p. 333, ISBN 81-208-1596-3
- Arik, Kagan (2008). Austin, Peter (ed.). One Thousand Languages: Living, Endangered, and Lost (illustrated ed.). University of California Press. ISBN 978-0520255609. Retrieved 10 March 2014.
- Chén Zōngzhèn & Léi Xuǎnchūn. 1985. Xībù Yùgùyǔ Jiānzhì [Concise grammar of Western Yugur]. Peking.
- Clauson, Gerard (April 1965). "Review An Eastern Turki-English Dictionary by Gunnar Jarring". The Journal of the Royal Asiatic Society of Great Britain and Ireland. Royal Asiatic Society of Great Britain and Ireland (1/2). JSTOR 25202808.
- Coene, Frederik (8 October 2009). The Caucasus - An Introduction. Taylor & Francis. ISBN 978-0-203-87071-6.
- Tisastvustik; ein in türkischer Sprache bearbeitetes buddhistisches Sutra. I. Transcription und Übersetzung von W. Radloff. II. Bemerkungen zu den Brahmiglossen des Tisastvustik-Manuscripts (Mus. A. Kr. VII) von Baron A. von Stäel-Holstein (1910)
- Kahar Barat (2000). The Uygur-Turkic Biography of the Seventh-Century Chinese Buddhist Pilgrim Xuanzang: Ninth and Tenth Chapters. Indiana University, Research Institute for Inner Asian Studies. ISBN 978-0-933070-46-2.
- Giovanni Stary (1996). Proceedings of the 38th Permanent International Altaistic Conference (PIAC): Kawasaki, Japan, August 7-12, 1995. Harrassowitz Verlag in Kommission. ISBN 978-3-447-03801-0.