Mongolia is a landlocked country in East Asia. Bordered by Russia to the north and China to the south and southeast, it covers an area of 1,564,116 square kilometres (603,909 square miles), making it the 18th-largest country in the world and the second largest landlocked country after Kazakhstan, as well as the largest landlocked country that does not border an inland sea. With a population of 3.5 million, it is the world's most sparsely populated sovereign state. The country constitutes a significant portion of the Mongolian Plateau, and its natural environment is characterized by grassy steppe, mountains to the north and west, and the Gobi Desert to the south. Ulaanbaatar, the capital and largest city, is home to roughly half of the country's population.
The territory of modern-day Mongolia has been ruled by various nomadic empires, including the Xiongnu, the Xianbei, the Rouran, the First Turkic Khaganate, the Second Turkic Khaganate, the Uyghur Khaganate and others. In 1206, Genghis Khan founded the Mongol Empire, which became the largest contiguous land empire in history. His grandson Kublai Khan conquered China proper and established 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.