Tuoba ( Middle Chinese: thak b?t) also known as the Taugast or Tabgach ( Tabgaç), was a Xianbei clan in ancient China. 
The Tuoba founded the
Northern Wei (386-535) around the Yellow River delta and became increasingly sinicized. As a result, from 496, the name "Tuoba" disappeared by an edict of Emperor Xiaowen of Northern Wei, who adopted the Chinese language surname of Yuan ( ) instead. A surviving branch of the Tuoba established the state of ? Tuyuhun before submitting as a vassal of the Tang dynasty. Their Tangut subjects later established the Western Xia, whose rulers adopted the Chinese surname Li ( ). The ruling families of the ? Western Wei and Northern Zhou dynasties that followed the fall of Northern Wei were also of Tuoba ethnicity.
Alexander Vovin (2007) identifies the Tab?a? language as a Mongolic language. However, Chen (2005)  argues that Tuoba (Tab?a?) was a  Turkic language.
Tuoba people and their neighbours, c. III century AD
The distribution of the Xianbei people ranged from present day
Northeast China to Mongolia, and the Tuoba were one of the largest clans among the western Xianbei, ranging from present day Shanxi province and westward and northwestward. They established the state of Dai from 310-376 AD and ruled as the  Northern Wei from 386-536. The Tuoba states of Dai and Northern Wei also claimed to possess the quality of earth in the Chinese Wu Xing theory. All the chieftains of the Tuoba were revered as emperors in the and the Book of Wei . Some scholars suggest that the Tuoba were History of the Northern Dynasties proto-Mongols (and spoke a proto- Mongolic language) or belonged to their own branch of Ural-Altaic language family,  although some also suggest that instead of being related to the Mongols, they were perhaps related to the  Turkic peoples (and spoke a proto- Turkic language).    In the opinion of Peter Boodberg, much of the Tuoba vocabulary was "essentially Turkish with a certain admixture of Mongolian elements".  On the other hand, Edwin Pulleyblank "concluded that it was Mongolian."  Chen Sanping observes that the Tuoba language "had both" elements.  On the other hand, Liu Xueyao stated that Tuobas may have had their own language which should not be assumed to be identical with any other known languages.  The  Rourans considered that Tuoba and Rourans descended from common ancestors.
Also a historian of the  Northern Wei noted that Rourans descended from Xianbei.
Northern Wei started to arrange for Chinese elites to marry daughters of the Xianbei Tuoba royal family in the 480s. More than fifty percent of Tuoba Xianbei princesses of the Northern Wei were married to southern Chinese men from the imperial families and aristocrats from southern China of the  Southern dynasties who defected and moved north to join the Northern Wei. Some Chinese exiled royalty fled from southern China and defected to the Xianbei. Several daughters of the Xianbei Tuoba  Emperor Xiaowen of Northern Wei were married to Chinese elites, the Han Chinese Liu Song royal Liu Hui , married Princess Lanling ? of the Northern Wei,      Princess Huayang ? to Sima Fei , a descendant of  Jin dynasty (265-420) royalty, Princess Jinan ? to Lu Daoqian , Princess Nanyang to Xiao Baoyin , a member of Southern Qi royalty.  Emperor Xiaozhuang of Northern Wei's sister the Shouyang Princess was wedded to the Liang dynasty ruler Emperor Wu of Liang's son Xiao Zong . 
Eastern Jin dynasty ended Northern Wei received the Han Chinese Jin prince Sima Chuzhi ? as a refugee. A Northern Wei Princess married Sima Chuzhi, giving birth to Sima Jinlong ?. Northern Liang Xiongnu King Juqu Mujian's daughter married Sima Jinlong. 
Chieftains of Tuoba Clan 219-377 (as Princes of Dai 315-377)
Grousset, Rene (1970). The Empire of the Steppes. Rutgers University Press. pp. 60-65. ISBN . 0-8135-1304-9
^ Vovin, Alexander. 2007. 'Once again on the Tab?a? language.' Mongolian Studies XXIX: 191-206.
^ Chen, Sanping 2005. Turkic or Proto-Mongolian? A Note on the Tuoba Language. Central Asiatic Journal 49.2: 161-73.
Grousset, Rene (1970). The Empire of the Steppes. Rutgers University Press. p. 57. ISBN . 0-8135-1304-9
^ a b
Holcombe 2001, p. 132.
Holcombe 2011, p. 65.
Kang-i Sun Chang,Stephen Owen (2010). The Cambridge History of Chinese Literature, Vol. 1. Cambridge University Press. p. 272.
Evelyn S. Rawski (2015). Early Modern China and Northeast Asia. p. 123.
Mote, Frederick W. (2003). Imperial China 900-1800. p. 170.
Charles O. Hucker (1975). China's Imperial Past: An Introduction to Chinese History and Culture. Stanford University Press. p. 136-137.
Charles Holcombe (2001). The Genesis of East Asia: 221 B.C. - A.D. 907. p. 132.
Holcombe 2001, p. 248
^ Liu Xueyao p. 83-86
Hyacinth (Bichurin), Collection of information on peoples lived in Central Asia in ancient times, 1950. p.209
Rubie Sharon Watson (1991). . University of California Press. pp. 80-. Marriage and Inequality in Chinese Society ISBN . 978-0-520-07124-7
Tang, Qiaomei (May 2016). Divorce and the Divorced Woman in Early Medieval China (First through Sixth Century) (PDF) (A dissertation presented by Qiaomei Tang to The Department of East Asian Languages and Civilizations in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the subject of East Asian Languages and Civilizations). Cambridge, Massachusetts: Harvard University. pp. 151, 152, 153.
. Australian National University, Department of Far Eastern History. 1983. p. 86. Papers on Far Eastern History
Hinsch, Bret (2018). . Rowman & Littlefield. p. 97. Women in Early Medieval China ISBN . 978-1538117972
Hinsch, Bret (2016). . Rowman & Littlefield. p. 72. Women in Imperial China ISBN . 978-1442271661
Lee, Jen-der (2014). "9. Crime and Punishment The Case of Liu Hui in the Wei Shu". In Swartz, Wendy; Campany, Robert Ford; Lu, Yang; Choo, Jessey (eds.). Early Medieval China: A Sourcebook (illustrated ed.). Columbia University Press. pp. 156-165. ISBN . 978-0231531009
Australian National University. Dept. of Far Eastern History (1983). . Australian National University, Department of Far Eastern History. pp. 86, 87, 88. Papers on Far Eastern History, Volumes 27-30
. Metropolitan Museum of Art. 2004. pp. 30-. China: Dawn of a Golden Age, 200-750 AD ISBN . 978-1-58839-126-1
. BRILL. 22 September 2014. pp. 1566-. Ancient and Early Medieval Chinese Literature (vol.3 & 4): A Reference Guide, Part Three & Four ISBN . 978-90-04-27185-2
. Metropolitan Museum of Art. 2004. pp. 18-. China: Dawn of a Golden Age, 200-750 AD ISBN . 978-1-58839-126-1
^ No known given name survives.
"Research of T'o-pa language (5th century AD)", T'oung Pao, 39/4-5, 1950 [ "Recherches sur les parlers T'o-pa (5e siècle après J.C.)"] (in French) Subject: Toba Tatar language Boodberg, P.A.
"The Language of the T'o-pa Wei", Harvard Journal of Asiatic Studies, Vol. 1, 1936. Clauson, G.
"Turk, Mongol, Tungus", Asia Major, New Series, Vol. 8, Pt 1, 1960, pp. 117-118 Grousset, R.
"The Empire of the Steppes: A History of Central Asia", Rutgers University Press, 1970, p. 57, 63-66, 557 Note 137, ISBN 0-8135-0627-1 
Lee Jen-der (2014), "Crime and Punishment: The Case of Liu Hui in the , Wei Shu" , New York: Columbia University Press, pp. 156-165, Early Medieval China: A Sourcebook ISBN 978-0-231-15987-6 . Pelliot, P.A.
"L'Origine de T'ou-kiue; nom chinoise des Turks", T'oung Pao, 1915, p. 689 Pelliot, P.A.
"L'Origine de T'ou-kiue; nom chinoise des Turks", Journal Asiatic, 1925, No 1, p. 254-255 Pelliot, P.A.
"L'Origine de T'ou-kiue; nom chinoise des Turks", T'oung Pao, 1925-1926, pp. 79-93; Zuev, Y.A. "Ethnic History Of Usuns", Works of Academy of Sciences Kazakh SSR, History, Archeology And Ethnography Institute, Alma-Ata, Vol. VIII, 1960, (In Russian)