Since the prehistoric times, Mongolia has been inhabited by nomads who, from time to time, formed great confederations that rose to power and prominence. Common institutions were the office of the Khan, the Kurultai (Supreme Council), left and right wings, imperial army (Keshig) and the decimal military system. The first of these empires, the Xiongnu of undetermined ethnicity, were brought together by Modu Shanyu to form a confederation in 209 BC. Soon they emerged as the greatest threat to the Qin dynasty, forcing the latter to construct the Great Wall of China. It was guarded by up to almost 300,000 soldiers during Marshal Meng Tian's tenure, as a means of defense against the destructive Xiongnu raids. The vast Xiongnu empire (209 BC–93 AD) was followed by the Mongolic Xianbei empire (93–234 AD), which also ruled more than the entirety of present-day Mongolia. The Mongolic Rouran Khaganate (330–555), of Xianbei provenance was the first to use "Khagan" as an imperial title. It ruled a massive empire before being defeated by the Göktürks (555–745), an even larger empire. The Göktürks laid siege to Panticapaeum, present-day Kerch, in 576. They were succeeded by the Uyghur Khaganate (745–840) who were defeated by the Kyrgyz. The Mongolic Khitans, descendants of the Xianbei, ruled Mongolia during the Liao dynasty (907–1125), after which the Khamag Mongol (1125–1206) rose to prominence. Lines 3–5 of the memorial inscription of Bilge Khagan (684–737) in central Mongolia summarizes the time of the Khagans: .mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 32px}.mw-parser-output .templatequotecite{line-height:1.5em;text-align:left;margin-top:0}@media(min-width:500px){.mw-parser-output .templatequotecite{padding-left:1.6em}} In battles they subdued the nations of all four sides of the world and suppressed them. They made those who had heads bow their heads, and who had knees genuflect them. In the east up to the Kadyrkhan common people, in the west up to the Iron Gate they conquered... These Khagans were wise. These Khagans were great. Their servants were wise and great too. Officials were honest and direct with people. They ruled the nation this way. This way they held sway over them. When they died ambassadors from Bokuli Cholug (Baekje Korea), Tabgach (Tang China), Tibet (Tibetan Empire), Avar (Avar Khaganate), Rome (Byzantine Empire), Kirgiz, Uch-Kurykan, Otuz-Tatars, Khitans, Tatabis came to the funerals. So many people came to mourn over the great Khagans. They were famous Khagans.[29] Mongol empire to early 20th century Main articles: Mongol Empire, Mongolia under Yuan rule, Northern Yuan dynasty, Dzungar Khanate, and Mongolia under Qing rule See also: List of medieval Mongol tribes and clans, List of Mongol states, and List of Mongol rulers Mongol Empire expansion (1206–1294) In the chaos of the late 12th century, a chieftain named Temüjin finally succeeded in uniting the Mongol tribes between Manchuria and the Altai Mountains. In 1206, he took the title Genghis Khan, and waged a series of military campaigns – renowned for their brutality and ferocity – sweeping through much of Asia, and forming the Mongol Empire, the largest contiguous land empire in world history. Under his successors it stretched from present-day Poland in the west to Korea in the east, and from parts of Siberia in the north to the Gulf of Oman and Vietnam in the south, covering some 33,000,000 square kilometres (13,000,000 sq mi),[30] (22% of Earth's total land area) and had a population of over 100 million people (about a quarter of Earth's total population at the time). The emergence of Pax Mongolica also significantly eased trade and commerce across Asia during its height.[31][32] After Genghis Khan's death, the empire was subdivided into four kingdoms or Khanates. These eventually became quasi-independent after the Toluid Civil War (1260–1264), which broke out in a battle for power following Möngke Khan's death in 1259. One of the khanates, the "Great Khaanate", consisting of the Mongol homeland and most of modern-day China, became known as the Yuan dynasty under Kublai Khan, the grandson of Genghis Khan. He set up his capital in present-day Beijing. After more than a century of power, the Yuan dynasty was overthrown by the Ming dynasty in 1368, and the Yuan court fled to the north, thus becoming the Northern Yuan dynasty. As the Ming armies pursued the Mongols into their homeland, they successfully sacked and destroyed the Mongol capital Karakorum and other cities. Some of these attacks were repelled by the Mongols under Ayushridar and his general Köke Temür.[33] After the expulsion of the Yuan rulers from China proper, the Mongols continued to rule their homeland, known in historiography as the Northern Yuan dynasty. With the division of the Mongol tribes, it was subsequently also known as "The Forty and the Four" (Döčin dörben) among them.[34] The next centuries were marked by violent power struggles among various factions, notably the Genghisids and the non-Genghisid Oirats, as well as by several Ming invasions (such as the five expeditions led by the Yongle Emperor). Genghis Khan, the first Mongol Emperor In the early 16th century, Dayan Khan and his khatun Mandukhai reunited all Mongol groups under the Genghisids. In the mid-16th century, Altan Khan of the Tümed, a grandson of Dayan Khan – but not a hereditary or legitimate Khan – became powerful. He founded Hohhot in 1557. After he met with the Dalai Lama in 1578, he ordered the introduction of Tibetan Buddhism to Mongolia. (It was the second time this had occurred.) Abtai Khan of the Khalkha converted to Buddhism and founded the Erdene Zuu monastery in 1585. His grandson Zanabazar became the first Jebtsundamba Khutughtu in 1640. Following the leaders, the entire Mongolian population embraced Buddhism. Each family kept scriptures and Buddha statues on an altar at the north side of their yurt. Mongolian nobles donated land, money and herders to the monasteries. As was typical in states with established religions, the top religious institutions, the monasteries, wielded significant temporal power in addition to spiritual power.[35] The last Khagan of Mongols was Ligden Khan in the early 17th century. He came into conflicts with the Manchus over the looting of Chinese cities, and also alienated most Mongol tribes. He died in 1634. By 1636, most of the Inner Mongolian tribes had submitted to the Manchus, who founded the Qing dynasty. The Khalkha eventually submitted to Qing rule in 1691, thus bringing all of today's Mongolia under Manchu rule. After several Dzungar–Qing Wars, the Dzungars (western Mongols or Oirats) were virtually annihilated during the Qing conquest of Dzungaria in 1757 and 1758.[36] Altan Khan (1507–1582) founded the city of Hohhot, helped introduce Buddhism and originated the title of Dalai Lama. Some scholars estimate that about 80% of the 600,000 or more Dzungar were killed by a combination of disease and warfare.[37] Outer Mongolia was given relative autonomy, being administered by the hereditary Genghisid khanates of Tusheet Khan, Setsen Khan, Zasagt Khan and Sain Noyon Khan. The Jebtsundamba Khutuktu of Mongolia had immense de facto authority. The Manchu forbade mass Chinese immigration into the area, which allowed the Mongols to keep their culture. The Oirats who migrated to the Volga steppes in Russia became known as Kalmyks. The main trade route during this period was the Tea Road through Siberia; it had permanent stations located every 25 to 30 kilometres (16 to 19 mi), each of which was staffed by 5–30 chosen families. Until 1911, the Qing dynasty maintained control of Mongolia with a series of alliances and intermarriages, as well as military and economic measures. Ambans, Manchu "high officials", were installed in Khüree, Uliastai, and Khovd, and the country was divided into numerous feudal and ecclesiastical fiefdoms (which also placed people in power with loyalty to the Qing). Over the course of the 19th century, the feudal lords attached more importance to representation and less importance to the responsibilities towards their subjects. The behavior of Mongolia's nobility, together with usurious practices by Chinese traders and the collection of imperial taxes in silver instead of animals, resulted in widespread poverty among the nomads. By 1911 there were 700 large and small monasteries in Outer Mongolia; their 115,000 monks made up 21% of the population. Apart from the Jebtsundamba Khutuktu, there were 13 other reincarnating high lamas, called 'seal-holding saints' (tamgatai khutuktu), in Outer Mongolia. Modern history Main articles: Mongolian Revolution of 1911, Bogd Khanate of Mongolia, Mongolian Revolution of 1921, Mongolian People's Republic, Mongolian Revolution of 1990, and History of modern Mongolia The eighth Jebtsundamba Khutuktu, Bogd Khaan Map of unified Mongolia in 1917 With the fall of the Qing dynasty in 1911, Mongolia under the Bogd Khaan declared its independence. However, the newly established Republic of China considered Mongolia to be part of its own territory. Yuan Shikai, the President of the Republic of China, considered the new republic to be the successor of the Qing. Bogd Khaan said that both Mongolia and China had been administered by the Manchu during the Qing, and after the fall of the Qing dynasty in 1911, the contract of