Various nomadic empires, including the Xiongnu (3rd century BC–1st century AD), the Xianbei state ( AD 156–234), the Rouran Khaganate (330–555), the First (552–603) and Second Turkic Khaganates (682–744) and others, ruled the area of present-day Mongolia. The Khitan people, who used a para-Mongolic language, founded an empire under the Liao dynasty (916–1125), and ruled Mongolia and portions of North China, northern Korea, and the present-day Russian Far East.

In 1206, Genghis Khan was able to unite the Mongol tribes, forging them into a fighting force which went on to establish the largest contiguous empire in world history, the Mongol Empire (1206–1368). After the fragmentation of the Mongol Empire, Mongolia came to be ruled by the Yuan dynasty (1271–1368) based in Khanbaliq (modern Beijing) and administered as part of the Lingbei Province. Buddhism in Mongolia began with the Yuan emperors' conversion to and dissemination of Tibetan Buddhism.

After collapse of the Mongol-led Yuan dynasty in 1368, the Yuan court retreated to the Mongolian Plateau, marking the start of the Northern Yuan dynasty (1368–1635), and the Mongols returned to their earlier patterns of internal strife and their old shamanist ways. However, Buddhism would reemerge in the 16th century.

At the end of the 17th century, Mongolia became part of the Manchu-led Qing dynasty. During the Xinhai Revolution, Mongolia declared independence from Qing but had to struggle until 1921 to firmly establish de facto independence and until 1945 to gain international recognition. As a consequence, Mongolia came under strong Soviet influence. In 1924, the Mongolian People's Republic was declared, and Mongolian politics began to follow the same patterns as Soviet politics of the time. The revolutions of 1989 and the protests of the year that followed led to a multi-party system, a transition to a market economy, and the creation of a new constitution in 1992.

Prehistory

The climate of Central Asia became dry after the large tectonic collision between the Indian plate and the Eurasian plate. This impact threw up the massive chain of mountains known as the Himalayas. The Himalayas, Greater Khingan and Lesser Khingan mountains act like a high wall, blocking the warm and wet climate from penetrating into Central Asia. Many of the mountains of Mongolia were formed during the Late Neogene and Early Quaternary periods. The Mongolian climate was more humid hundreds of thousands of years ago. Mongolia is known to be a source of paleontological discoveries. The first scientifically confirmed dinosaur eggs were found in Mongolia during the 1923 expedition of the American Museum of Natural History, led by Roy Chapman Andrews.

During the middle to late Eocene Epoch, Mongolia was the home of many Paleogene mammals including the Sarkastodon and Andrewsarchus.

Homo erectus possibly inhabited Mongolia up to 800,000 years ago but fossils of Homo erectus have not yet been found in Mongolia. Stone tools have been found in the Gobi Desert, perhaps dating back as much as 800,000 years.Хүрээлэнгийн эрдэм шинжилгээний ажлын ололт амжилт, Institute of Mongolian Archaeology Important prehistoric sites are the Paleolithic cave drawings of the Khoid Tsenkheriin Agui (Northern Cave of Blue) in Khovd province,Eleanora Novgorodova, Archäologische Funde, Ausgrabungsstätten und Skulpturen, in Mongolen (catalogue), pp. 14-20 and the Tsagaan Agui (White Cave) in Bayankhongor Province.Davaadorzhiĭn Ganbold, Da Haliun – Facts about Mongolia, p.34 A Neolithic farming settlement has been found in Dornod Province. Contemporary findings from western Mongolia include only temporary encampments of hunters and fishers. Horse-riding nomadism has been documented by archeological evidence in Mongolia during the Copper and Bronze Age Afanasievo culture (3500–2500 BC).

The Slab-grave culture of the late Bronze and early Iron Age, related to the proto-Mongols, spread over northern, central and eastern Mongolia, Inner Mongolia, Northwest China (Xinjiang, Qilian Mountains etc.), Manchuria, Lesser Khingan, Buryatia, Irkutsk Oblast and Zabaykalsky Krai.Tumen D., "Anthropology of Archaeological Populations from Northeast Asia " (PDF) pages 25, 27 This culture is the main archaeological find of Bronze Age Mongolia.

Deer stones (also known as reindeer stones) and Khirigsüürs (small kurgans) are probably from this era; other theories date the deer stones as 7th or 8th centuries BC. Deer stones are ancient megaliths carved with symbols that can be found all over central and eastern Eurasia but are concentrated largely in Mongolia and Siberia. Most deer stones occur in association with ancient graves; it is believed that stones are the guardians of the dead. There are around 700 deer stones known in Mongolia of a total of 900 deer stones that have been found in Central Eurasia and South Siberia. Their true purpose and creators are still unknown. Some researchers claim that deer stones are rooted in shamanism and are thought to have been set up during the Bronze Age around 1000 BC, and may mark the graves of important people. Later inhabitants of the area likely reused them to mark their own burial mounds, and perhaps for other purposes. In Mongolia, the Lake Baikal area, and the Sayan and Altai Mountains, there are 550, 20, 20, and 60 known deer stones respectively. Moreover, there are another 20 deer stones in Kazakhstan and the Middle East (Samashyev 1992) and 10 further west, specifically in Ukraine and parts of the Russian Federation, including the provinces of Oren burg and the Caucasus, and near the Elbe River (Mongolian History 2003). According to H.L. Chlyenova, the artistic deer image originated from the Sak tribe and its branches (Chlyenova 1962). Volkov believes that some of the methods of crafting deer stone art are closely related to Scythians (Volkov 1967), whereas Mongolian archaeologist D. Tseveendorj regards deer stone art as having originated in Mongolia during the Bronze Age and spread thereafter to Tuva and the Baikal area (Tseveendorj 1979).

A vast Iron Age burial complex from the 5th to 3rd centuries BC, later also used by the Xiongnu, has been unearthed near Ulaangom.

Before the 20th century, some scholars assumed that the Scythians descended from the Mongolic people. The Scythian community inhabited western Mongolia in the 5th to 6th centuries BC. In 2006, the mummy of a Scythian warrior, which is believed to be about 2,500 years old was a 30-to-40-year-old man with blond hair, was found in the Altai Mountains, Mongolia.

In historical times Eurasian nomads were concentrated on the steppe lands of Central Asia.

By the 8th century BC, the inhabitants of the western part of Mongolia evidently were nomadic Indo-European migrants, either Scythians or Yuezhi. In central and eastern parts of Mongolia were many other tribes that were primarily Northeast Asian in their ethnologic characteristics.

With the appearance of iron weapons by the 3rd century BC, the inhabitants of Mongolia had begun to form clan alliances and lived a hunter and herder lifestyle. The origins of more modern inhabitants are found among the forest hunters and nomadic tribes of Inner Asia. They inhabited a great arc of land extending generally from the Korean Peninsula in the east, across the northern tier of China to present-day Kazakhstan and to the Pamir Mountains and Lake Balkash in the west. During most of recorded history, this has been an area of constant ferment from which emerged numerous migrations and invasions to the southeast (into China), to the southwest (into Transoxiana—modern Uzbekistan, Iran, and India), and to the west (across Scythia toward Europe).

Ancient period

The area of modern Mongolia has been inhabited by groups of nomads since ancient times. The ancient population had a nomadic and hunter lifestyle and lived fairly undisturbed. While most of Central Eurasia had a fairly similar nomadic lifestyle where moving in and around national boundaries and mixing with different settlements was common, the Mongolian steppes were a unique environment because migration was limited by natural barriers such as the Altai Mountains in the west, the Gobi Desert in the south and the freezing wastelands of Siberia in the north, all unsuitable for nomads. These greatly limited migrations, although they also kept out invaders. The clans in Mongolia only allied with other Mongolian clans, with which they shared the same language, religion, and way of life. This would later be a huge advantage in uniting the people in Mongolia against the threat of the expanding Chinese empires. There were repeated conflicts with the Chinese dynasties of Shang and especially Zhou, which had begun conquering and enslaving the Mongolic people in an expansive drift. During the Warring States period (475–221 BC) in China, the northern states of Zhao, Yan, and Qin had begun to encroach into and conquer parts of southern Mongolia. By the time the Qin dynasty had united all of China's kingdoms into one empire in the 3rd century BC, the Xiongnu confederacy had formed in the Mongolian plains, transforming all of the independent clans into one single state that reassured their safety and independence from an expanding Qin.

Xiongnu (209 BC – 93 AD)

The establishment of the Xiongnu empire in Mongolia in the 3rd century BC marks the beginning of statehood in the territory of Mongolia.

The identity of the ethnic core of Xiongnu has been a subject of varied hypotheses and some scholars, including Alexey Okladnikov, Paul Pelliot and Byambyn Rinchen,Ts. Baasansuren "The scholar who showed the true Mongolia to the world", Summer 2010 vol. 6 (14) Mongolica, pp. 40 who insisted on a Mongolic origin.

There are many cultural similarities between the Xiongnu and Mongols such as yurt on cart, composite bow, board games, horn bow and long song.Н.Сэр-Оджав, Монголын эртний түүх. 1977 Mongolian long song is believed to date back at least 2,000 years.Mongolian traditional folk song UNESCO.org Mythical origin of the long song mentioned in "Book of Wei" (Volume 113).

The first significant appearance of nomads came late in the 3rd century BC, when the Chinese repelled an invasion of the Xiongnu across the Yellow River from the Gobi.

The founder of the Xiongnu empire was Toumen. He was violently succeeded by his son Modu Shanyu, who then conquered and unified various tribes. At the peak of its power, the Xiongnu confederacy stretched from Lake Baikal in the north to the Great Wall in the south and from the Tian Shan mountains in the west to the Greater Khingan ranges in the east. In the 2nd century BC the Xiongnu turned their attention westward to the region of the Altai Mountains and Lake Balkhash, inhabited by Indo-European-speaking nomadic peoples, including Yuezhi (Yüeh-chih in Wade–Giles), who had relocated from China's present-day Gansu Province as a result of their earlier defeat by the Xiongnu. Endemic warfare between these two nomadic peoples reached a climax in the latter part of the 3rd century and the early decades of the 2nd century BC; the Xiongnu were triumphant. The Yuezhi then migrated to the southwest where, early in the 2nd century, they began to appear in the Oxus (the modern Amu Darya) Valley, to change the course of history in Bactria, Iran, and eventually India.