A dynamic leader, he consolidated his power between the Xiongnu and conquered tribes, calling their leaders to an annual meeting at his headquarters in modern Outer Mongolia. There he took a census of people and animals and devised a system of government with himself as the supreme leader.
Maotun’s coming to power coincided with the collapse of the Qin dynasty in China, beginning with the death of the first emperor, followed by the suicide of General Meng Tian (Meng T’ien) in 210 b.c.e. (his powerful Chinese army had defeated the Xiongnu forces and built the Great Wall of China to keep them out of Chinese territories).
The Qin dynasty ended in 206 b.c.e., and four years of civil war ensued, ending with the founding of the Han dynasty by Liu Bang (Liu Pang). The collapse of the Qin had left the frontiers undefended and Liu Bang, known posthumously as Han Gaozu (Han Kao-tsu), decided to deal with the Xiongnu threat immediately.
In 200 b.c.e. he personally led 300,000 mostly infantry troops to war against the Xiongnu. Maotun and Gaozu met in battle near the modern city of Datong (Ta-tung) in Shanxi (Shansi) Province; Maotun won with his 400,000 cavalry, and Gaozu narrowly escaped capture.
The two sides made peace in 198 b.c.e. The He qin (Ho-ch’in) Treaty declared the two sides as equals, demarcated their boundary along the Great Wall, and stipulated gifts of silver, silk, food, and liquor in fixed quantities several times a year from the Han to the Xiongnu.
In addition, Gaozu promised his only daughter by his wife Empress Lu to marry Maotun. The empress vetoed the marriage of her daughter, and they adopted a relative, gave her the rank of princess, and sent her to wed Maotun.
When Gaozu died in 195 b.c.e. Maotun proposed to Empress Lu, suggesting that they marry and unite their empires. She was furious but had to refuse politely. A second Han princess was sent to marry him in 192 b.c.e.
The Xiongnu empire continued to expand under Maotun. They were victorious against another nomadic people called the Yuezhi (Yueh-chih) and expelled them from the Gansu (Kansu) Corridor. The main Yuezhi tribe fled all the way to Afghanistan where they remained. Before his death in 174 b.c.e.
Maotun negotiated the Heqin treaties with the Han, each time increasing the amount of gifts the Han had to give to the Xiongnu. Successive Han rulers submitted to Xiongnu terms because the Chinese economy had been damaged by previous civil wars, and peace was necessary for recovery.
Maotun’s son and grandson were also powerful leaders, following Maotun’s example of intimidating the Han. It was not until 134 b.c.e. that the Han ended the era of the Heqin treaties and began a long-term war that ended in the defeat of the Xiongnu.