In ancient times the Uyghurs lived in present-day Mongolia. There they established a kingdom. In 640, the Kyrgyz invaders defeated them. Some Uighurs then moved to northern China. These are called Uyghur or Yellow Uyghur. Their language is different from Uyghur. Another large group of Uyghurs settled in the Turfan region of northeastern China , where they established another state , which lasted until the 15th century. The languages spoken by these people are now regarded as dialects of the Uyghur Turfan and Kashgar dialects . The word Uyghur was lost when the Chagatai dynasty was established in Central Asia. The official language of the kingdom was the artificial Chagatai language, a mixture of Uzbek and Uighur. The word Uyghur was revived in 1921, and the term was officially used to identify the Uyghur people. The current standard Uighur language is very different from the previous Uighur language of the Chagatai dynasty. In the 19th century, large numbers of Uighurs from various parts of East Turkistan began to settle on the banks of the Ili River. The modern Uyghur language was born out of a mixture of their spoken Uyghur dialect and the Ilya Valley dialect. The Uyghurs have been recognized as one of China's 57 ethnic groups. Uyghur is the provincial official language of Xinjiang. It is used everywhere in education and in the media. The language is being used in about 50 newspapers and periodicals and 6 television channels. There is education in Uyghur from secondary to university level. Older Uyghurs only speak the Uyghur language. On the other hand, the younger generation is fluent in Chinese besides Uyghur. Uighur is the mother tongue of 80% of the 300,000 Uyghur people in Kazakhstan . Most young and educated Uighurs in Kazakhstan can also speak Russian.