The Rise of Mongolia The Mongols originated from a tribe in the Wangjian River (today's Erguna River) basin in ancient times. They first appeared in the "Old Tang Book" under the name "Mengwu Shiwei".After the collapse of the Uighur Khanate in 840 AD, most of the tribe moved westward, and the river gradually merged with the Turkic-speaking residents who remained on the Mongolian plateau.The language developed into Mongolian writing under the influence of Turkic languages, and the economic life was also influenced by Turkic languages, transitioning from nomadic to predominantly nomadic.