The proto-Mongols emerged from an area that had been inhabited by humans and predecessor hominin species as far back as 45,000 years ago during the Upper Paleolithic. The people there went through the Bronze and Iron Ages, forming tribal alliances, peopling, and coming into conflict with early polities in the Central Plain.
The proto-Mongols formed various tribal kingdoms that fought against each other for supremacy, such as the Rouran Khaganate (330–555) until it was defeated by the Göktürks, who founded the First Turkic Khaganate (552–744), which in turn was subdued by the growing strength of the Tang dynasty. The destruction of the Uyghur Khaganate (744–848) by the Yenisei Kyrgyz resulted in the end of Turkic dominance on the Mongolian Plateau.
The para-Mongol Khitan people founded a Chinese dynasty known as the Liao dynasty (916–1125) and ruled Mongolia and portions of the eastern coast of Siberia now known as the Russian Far East, northern Korea, and North China. Over the next few hundred years, the Jurchens in China subtly encouraged warfare among the Mongols as a way of keeping them distracted from invading China proper.
In the 12th century, Genghis Khan was able to unite or conquer the warring tribes, forging them into a unified fighting force that went on to create the largest contiguous empire in world history, the Mongol Empire, which was finally able to conquer the whole of China proper—beginning with his invasion of the Khitan-led Western Liao dynasty and the Tangut-led Western Xia dynasty, and ending with his grandson Kublai Khan's conquest of the Southern Song dynasty. Kublai then founded the Yuan dynasty of China in 1271.
Origins
Archaeological evidence suggests that Upper Paleolithic hominins inhabited Mongolia as early as 45,000 years ago.
By the first millennium BC, bronze-working peoples lived on the Mongolia Plateau. 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 parts 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).
By the eighth century BC, the inhabitants of western Mongolia evidently were nomadic Indo-European speakers, either Scythians or Yuezhi. In central and eastern parts of Mongolia were many other tribes, such as the Slab Grave culture and the Ordos culture.
Xiongnu
According to a number of sources, one of the ancestors of the Mongols were the Xiongnu, although it is not yet known whether they were proto-Mongols.
The Xiongnu were a group of nomads who dominated the Asian steppe from the late 3rd century BC for more than 500 years. The Xiongnu invasions prompted the kingdoms of North China to begin erecting what later became the Great Wall.
The identity of the ethnic core of Xiongnu has been a subject of varied hypotheses and some scholars, including A. Luvsandendev, Bernát Munkácsy, Henry Hoyle Howorth, Bolor Erike, Alexey Okladnikov, Peter Simon Pallas, Isaac Jacob Schmidt, Hyacinth and Byambyn Rinchen, insisted on a proto-Mongolian origin. There are several other theories about the ethnolinguistic identity of the Xiongnu, such as Turkic, Yeniseian, Iranian, Uralic, multiethnic.
There are many cultural similarities between the Xiongnu and Mongols such as yurt on cart, mounted use of the composite bow, board game, horn bow and long song. The Mongolian long song is believed to date back at least 2000 years. A mythical origin of the long song is mentioned in the Book of Wei, volume 113.