Tatar was one of the five major tribal confederations in the Mongolian Plateau in the 12th century. The name "Tatar" was first transliterated in Book of Song as 大檀 Dàtán and 檀檀 Tántán as other names of the Rourans, who were of Proto-MongolicDonghu ancestry. Songshu and Liangshuconnected Rourans to the earlier Xiongnu while Weishu traced the Rouran's origins back to the Donghu. Xu proposed that "the main body of the Rouran were of Xiongnu origin" and Rourans' descendants, namely Da Shiwei, contained Turkic elements to a great extent. Even so, the Xiongnu's language is still unknown, and Chinese historians routinely ascribed Xiongnu origins to various nomadic groups, yet such ascriptions do not necessarity indicate the subjects' exact origins: for examples, Xiongnu ancestry was ascribed to Turkic-speaking Göktürks and Tiele as well as Para-Mongolic-speaking Kumo Xi and Khitans. The first precise transcription of the Tatar ethnonym was on the Orkhon inscriptions, specifically, the Kul Tigin and Bilge Khagan monuments as translit=Otuz Tatar Bodun and translit=Tuquz Tatar referring to the Tatar confederation. Subsequently, the wider region was referred to by Europeans as "Tartary" or "Tartaria". The Tatars' Rouran ancestors founded Rouran Khaganate in the 5th century; Rourans roamed today Mongolia in summer and crossed the Gobi desert southwards in winter in search of pastures. Among the Rourans' subjects were the Ashina tribe, who overthrew their Rouran overlords in 555. One branch of the dispersed Rourans migrated to Greater Khinganmountain range where they renamed themselves after Tantan, a historical Khagan, and gradually incorporated themselves into the Shiwei tribal complex and emerged as 大室韋 Da Shiwei. Latter Göktürks acknowledged Tatars as formidable enemies. By the 10th century, Tatars became subjects of the Khitan Liao dynasty. After the fall of the Liao, the Tatars experienced pressure from the Jurchen Jin dynasty and were urged to fight against the other Mongol tribes. The Tatars lived on the fertile pastures around Hulun Nuur and Buir Nuur and occupied a trade route to China in the 12th century. Kara-khanid scholar Mahmud al-Kashgari noted that the Tatars are bilingual, speaking Turkic alongside their own language. The Tatars were subjugated by Mongol leader Temujin, who subsequently, as Genghis Khan, founded the Mongol Empire. Under the leadership of his grandson Batu Khan, Tatars accompanied Mongols westwards, driving with them many of the Turkic peoples toward the plains of Russia in the Turkic migrations. Their name Tatar was used by Russians and Europeans to denote Mongols as well as Turkic peoples under Mongol rule, especially in the Golden Horde. Later, it was used for any Turkic or even Mongolic speaking people encountered by Russians. Eventually however, the name stuck onto the Turkic Muslims of Ukraine and Russia, namely, the descendants of Muslim Volga Bulgars, Kipchaks, and Cumans, and Turkicized Mongols or Turko-Mongols, as well as other Turkic speaking peoples.
