In 1170 when Tie Muzhen was still a boy, his father was poisoned by a group of Tatars, and the Kiyat tribe broke up and scattered, abandoning their chief's family and leaving Tie Muzhen's mother, Ho'elun, to raise her children alone. Accounts of Tie Muzhen glorify Tie Muzhen as intelligent, brave, and an adept fighter, even from an early age and as such a potential threat to the leaders of other tribes of the steppe. As a young man, despite extreme hardships, he repeatedly met perils and endured crises through force of character and willpower.

However, as his power and influence in Mongol society grew, Tie Muzhen was not averse to terminating such alliances if it was to his advantage. In 1189, after he was elected the new leader of the Kiyat, he embarked on a series of military campaigns to unify the peoples of the steppe. In fact, he even betrayed and killed blood brothers such as his childhood friend Jamukha, and the Ong Khan of the Kereyid tribes. In 1204, he defeated Naiman, his last serious opponent。

In 1206, after a series of skilful victories, Tie Muzhen was acknowledged by the Mongol nobility as their supreme leader at a Khuriltai, a traditional meeting of tribal leaders to decide upon the future military and state matters. He was given the title of "Genghis Khan", which means "Oceanic Ruler", "Fierce Ruler", or "Khan of all Khans". Thus, a powerful unified Mongolian State was established.

Genghis Khan's campaigns and those of his descendants led to the creation of an immense empire that stretched from Hungary to Korea.

Genghis Khan was a supremely capable military leader and administrator. At the beginning, he divided all the Mongols into 95 Qian Hu, each of which was a subordinate to Genghis Khan's empire, thus he stabilized his regime through direct control of each Qian Hu. He was a careful planner who enforced the strictest discipline on all subordinates. Typically, he would send envoys to an opponent demanding their submission. If they acquiesced, he usually allowed their rulers to remain in power, so long as they paid taxes, furnished labor, and provided military service. If an opponent remained defiant, he attacked.

In 1205, 1207 and 1209, Genghis Khan attacked the Western Xia on the west three times, the Western Xia offered submission. In 1211, Genghis Khan moved south against the Jin and in 1215 he successfully besieged the Jin capital in the area of today's Peking. In 1218, he defeated the Liao Kingdom. In 1219, he moved west with around 200,000 troops to confront the Khwarazmian shah of Central Asia. Over the next several years, he besieged and took the cities of Bukhara, Samarkand, Herat, Nishapur, and Merv. He spent several years in Central Asia and enjoyed great military success; with his generals mounting successful raids and expeditions as far west as the Russian city of Novgorod. In 1224, upon hearing news that the Tanguts had rebelled, he returned east to Karakorum, his capital city in Mongolia. In the year of 1226, Genghis Khan crusaded for the Western Xia which was annihilated in 1227. Genghis Khan died in August, 1227, perhaps from a wound or a fever contracted during the suppression of the Tangut rebellion.

The unification of Mongolian tribes and the conquering of Jin and Western Xia by Genghis Khan laid the foundation for another peak of prosperity in China's history -- the united Yuan Dynasty (1271-1368).  

Genghis Khan left a legacy of more than just military might and skill. He supported artists and craftsmen, and promoted literacy among the Mongol people, who before his reign did not even possess an alphabet. Consequently, the alphabet of the neighboring Uygur people was adapted to the Mongol language. He also promoted a policy of religious toleration. All individuals and religions were equal under Mongol law. Having conquered such a vast domain, Genghis Khan became an enthusiastic promoter of trade. He and his successors encouraged and facilitated greater volumes of traffic throughout Asia. Steps were taken to provide effective policing in order to ensure the safety of travelers and the security of overland routes. Thus, for the first time, numerous European envoys, merchants, and craftsmen could travel in relative safety throughout Central Asia.

Though he was a conqueror whose exploits led to great destruction in terms of life and property, Genghis Khan did ultimately pave the way for an era of relative peace and security and increased cross-cultural contact.