The Yugurs, Yughurs, Yugu (; Western Yugur: Sarïg Yogïr; Eastern Yugur: Šera Yogor), traditionally known as Yellow Uyghurs, are a Turkic-Mongolic ethnic group and one of China's 56 officially recognized ethnic groups, consisting of 16,719 persons according to the 2000 census. The Yugur live primarily in Sunan Yugur Autonomous County in Gansu, China. They are mostly Tibetan Buddhists. Majority of Yugurs speak a Turkic language while Mongolic and Chinese are also used in Eastern provinces. The ethnic groups' current, official name, Yugur, derived from its autonym: the Turkic-speaking Yugur designate themselves as Yogïr, "Yugur" or Sarïg Yogïr, "Yellow Yugur" and the Mongolic-speaking Yugur likewise use either Yogor or Šera Yogor, "Yellow Yugur". Chinese historical documents have recorded these ethnonyms as Sālǐ Wèiwùr or Xīlǎgǔr. During the Qing dynasty, the Yugur were also called by a term that included "fān", the Classical Chinese term for Tibetic ethnic groups (, "Xīlǎgǔr Yellow Barbarians/Tibetans"). In order to distinguish both groups and their languages, Chinese linguists coined the terms Xībù Yùgùr, "Western Yugur" and Dōngbù Yùgùr, "Eastern Yugur" based on their geographical distribution. The Turkic-speaking Yugurs are considered to be the descendants of a group of Old Uyghurs who fled from Mongolia southwards to Gansu after the collapse of the Uyghur Khaganate in 840, where they established the prosperous Ganzhou Uyghur Kingdom (870-1036) with capital near present Zhangye at the base of the Qilian Mountains in the valley of the Ruo Shui. The population of this kingdom, estimated at 300,000 in Song chronicles, practised Manichaeism and Buddhism in numerous temples throughout the country. In 1037 the Yugur came under Tangut domination. The Gansu Uyghur Kingdom was forcibly incorporated into the Western Xia after a bloody war that raged from 1028 to 1036. As a result of Khizr Khoja’s invasion of Qumul, many residents who rejected conversion escaped to nearby Dunhuang and Hunan in China proper.