The Mongols are an ancient people. Chinese historians confirm the existence of Mongol tribes as early as the 10th century. At that time, the Mongols inhabited eastern Central Asia and northern Manchuria. Legend tells that the founders of the Mongol people were the Grey Wolf and the Beautiful Doe, but the first recognized Mongol was Bodonchar, who brought his people out of obscurity—an event dated to around 970. His descendants became the rulers of the Mongols, though the title remained largely nominal.

Numerous clans and tribes had their own chiefs. Emerging as a fragmented national entity, the Mongols became embroiled in regional politics. In Central Asia, power belonged to the Jurchen dynasty of the Tsing. The Jurchens periodically attacked nomadic peoples to drive them away from their borders. The Mongol rulers defended their territory without success, largely due to the division among many clans.

In 1162, Temüjin, the future Genghis, was born to Yesügei, a relative of the Mongol khan. At age ten, an enemy people, the Tatars, poisoned his father. Temüjin's family was later abandoned by relatives. The two widows of Yesügei thus lived together with six young children. The eldest, Temüjin, rose to prominence fairly quickly. By the time he reached twenty, he had succeeded in gathering a group of followers who supported him ardently.

In 1185, the great assembly of Mongol nobles proclaimed Temüjin khan of Mongolia and gave him the name Genghis. Although influential lords recognized Genghis, there was considerable opposition to him, and military action ensued. Genghis suffered defeats and likely went into exile, after which he had only a handful of supporters.

Around 1193, Genghis resumed his leadership role in Central Asia. He routed his enemies and rivals. Genghis began unifying the numerous Mongol tribes into a single Mongol nation. As a result, in 1206, the great assembly of Mongol leaders unanimously elected Genghis as khan of Mongolia. This time there was no one to oppose him. The year 1206 marks the establishment of the Mongol state. Genghis instituted a codified law in place of nomadic customs and reorganized the army, taxation, and state administration. He also introduced the Mongol alphabet, a derivative of Uighur script.