Mongolia i (Mongolian: ᠮᠤᠩᠭᠤᠯ
ᠤᠯᠤᠰ [Monggol Ulus] in Mongolian script; Монгол Улс [Mongol Uls] in Mongolian Cyrillic) is a sovereign state in east-central Asia. It is bordered by Russia to the north and China to the south, east and west. While they do not share a border, Mongolia is separated from Kazakhstan by only 36.76 kilometres (22.84 mi). Ulaanbaatar, the capital and largest city, is home to about 45% of the population.
The area of what is now Mongolia has been ruled by various nomadic empires, including the Xiongnu, the Xianbei, the Rouran, the Turkic Khaganate, and others. In 1206, Genghis Khan founded the Mongol Empire, and his grandson Kublai Khan conquered China to establish the Yuan dynasty. After the collapse of the Yuan, the Mongols retreated to Mongolia and resumed their earlier pattern of factional conflict, except during the era of Dayan Khan and Tumen Zasagt Khan. In the 16th century, Tibetan Buddhism began to spread in Mongolia, being further led by the Manchu-founded Qing dynasty, which absorbed the country in the 17th century. By the early 1900s, almost one-third of the adult male population were Buddhist monks.