There were four major battles between the Han dynasty and the Xiongnu, namely The Battle in Pingcheng, The Battle in Mayi, The Battle in Yanran Mountain, and The Battle in Wusun.
1. The Battle in Pingcheng
In the autumn of 201 BC, Xiongnu sent troops to surround Han Xin, the King of Han, in Mayi (present-day Shuo County, northern Shanxi). With little chance to win, Han Xin dispatched representatives to communicate with Xiongnu to negotiate peace several times and also seek help from the Han dynasty. On one hand, the Han dynasty rescued Han Xin by sending in armed forces. On the other hand, it condemned Han Xin’s act to make peace with Xiongnu. Han Xin became increasingly fearful of Emperor Gaozu who may put him to death and thus surrendered to Xiongnu in Mayi.
In 200 BC, Emperor Gaozu personally mobilized a force of 300,000 troops to defect Han Xin’s army in Tongdi (present-day the southeast of Qin County, Shanxi). At that time, Modu Chanyu assisted Han Xin by light cavalry. Just at the beginning of the fight, Han Xin and Xiongnu’s light cavalry lost the battle. Han Xin then fled to Xiongnu whereas Modu Chanyu led his army to attack Taiyuan and reach the border of Jinyang (present-day Taiyuan in Shanxi).
Upon his early arrival of Pingcheng (present-day the north of Datong in Shanxi) with his cavalrymen, Emperor Gaozu ordered Zhou Bo to attack three southeast city walls and moats, then join the major troops as backup forces. Just as Emperor Gaozu expected, Zhou Bo rescued him from a siege at last. Eventually, the Han army inflicted defeat to Xiongnu on the border of Jinyang (present-day Taiyuan in Shanxi).
From then on, Emperor Gaozu achieved peaceful relations with Xiongnu by political marriages in order to spare his full attention to handle the occupation of territory by local military powers. He sent ladies from the Han imperial clan to marry the Xiongnu leaders. A certain amount of gold, silk, flour, rice and wine were given to Xiongnu as presents every year. Business between the Hans and the Xiongnu were allowed.
2. The Battle in Mayi
In 133 BC, Nie Yi, a wealthy merchant in Mayi (present-day Shuo County, Shanxi) wrote to Emperor Wu. He persuaded the emperor to lure Xiongnu Chanyu into entering the Han territory further by significant interests. The Han army could lie in ambush to give Xiongnu a fatal attack.
In that June, Emperor Wu ordered a Han force of more than 300,000 troops, including infantry, cavalry and chariots, to lurk in the valleys near Mayi (present-day Shanxi). As soon as Xiongnu Chanyu entered Mayi, the Han troops would encircle them.
In addition, Emperor Wu assigned Nie Yi to be a spy. He pretended to flee to Xiongnu and reported to Junchen Chanyu that he could kill Mayi’s county magistrate and the assistant of the county magistrate so that the city would surrender.
The news excited Junchen Chanyu, who immediately prepared to send troops. Nie Yi killed two death rows, hung their heads up on the city gate, and told Junchen Chanyu that Mayi’s county magistrate and the assistant of the county magistrate were beheaded.
Junchen Chanyu was extremely pleased to receive the news. He led 100,000 cavalrymen, passed through the Great Wall by force and directly dashed to the fortress in Wuzhou. When he was about to arrive at Mayi in 100 li, he saw cattle and sheep everywhere but no sign of anybody. Growing suspicious, he attacked the fort nearby, caught the officer and was going to behead him. Threatened by death, the officer told Junchen Chanyu the truth and pointed out where the Han army lurked.
Finding out the trap, Junchen Chanyu trembled with fear. He gave an order to retreat quickly. Only after he departed from the Great Wall could he take a deep breath. Later, Junchen Chanyu firmly believed that the officer was a god descending from heaven to the earth to break the news to him about the Han army. He conferred a title “Heavenly King” upon the officer.
Junchen Chanyu had already left the fortress by the time the Han army received the news and hurried to the Great Wall. There was no point in chasing Junchen Chanyu since the Xiongnu had gone too far away. The Han army were forced to make a withdrawal.
From then on, Xiongnu Chanyu rejected any reconciliation. He even continuously invaded the checkpoints of the counties on the border. The incursion, which occurred frequently, usually penetrated deeply inside the counties.
3. The Battle in Yanran Mountain
In the March of 90 BC, Li Guangli mobilized a force of 130,000 troops to subjugate Xiongnu.
Knowing that the Han army would arrive, Xiongnu Chanyu moved the food supplies and gears for troops to the north, i.e. Zhijushui (present-day Selenga River in Mongolia). He personally led his major troops to the south, i.g. Guqieshui (present-day Yinhe River in the southern Bayankhongor Province, Mongolia) waiting for the Han army.
After leaving the frontier, Li Guangli struck down Wei Lu, the Left Grand Chief Commandant of Xiongnu. He further chased him to Zhijushui and Xiongnu moved back. Li Guangli led his 20,000 cavalry across Zhijushui, defeated the Left Wise King, and killed the Left Grand General.
Unfortunately, when the Han army marched back victorious, Xiongnu Chanyu encircled them in Yanran Mountain (present-day Khangai Mountains in Mongolia) knowing that Li Guangli tired out. The Han force of 130,000 troops was heavily defeated. Li Guangli surrendered to Xiongnu.
After the defeat in Yanran Mountain, Emperor Wu ceased to use military forces on Xiongnu because the Han economy went into recession and people grew weary of wars. He also issued an official order to reveal his deep reflection on his errors in dealing with Xiongnu and took measure on economic recovery to enhance productivity and restore the national power.
4. The Battle in Wusun
During Emperor Zhao’s reign, in order to ease the tension with the Han dynasty, Xiongnu released Su Wu, the Han ambassador who had been detained for 19 years. However, the Xiongnu cavalry still came to the northern frontier for countless times. In 73 BC, Xiongnu turned to attack Wusun, one of the city-states in the Western Regions, to demand a princess. Wusun requested military protection from the Han dynasty. A force of 130,000 troops, which comprised the Han and Wusun’s soldiers, were sent to attack Xiongnu. Unfortunately, the joint army did not meet Xiongnu’s major troops and returned in vain. Tian Shun and Tian Guangming, the Chief Generals, were condemned and forced to commit suicide.
In 71 BC, the khan of the Wusun, Liejiaomi, personally led 50,000 cavalry to invade the territory of the Lu-li King of the Right from west with Chang Hui, the Han envoy. It was a huge success.
In that winter, Xiongnu set out tens of thousands of cavalry to attack Wusun for revenge. On the occasion of heavy rain and snow, less than one tenth of the cavalry could survive. At that time, with Dingling attacking from the north, Wuhuan entering from the east, Wusun hitting from the west, Xiongnu was severely undermined. They were forced to move to the Western Regions for support. Both Han and Xiongnu scrambled for the Western Regions again. When they fiercely fought for Cheshi, Xiongnu faced an internal conflict. A power struggle broke out between Xianxianchan, the Rizhu King of the Right, who was in charge of the affairs in the Western Regions, and Tuqitang, the new Chanyu. The Rizhu King of the Right surrendered to the Han dynasty, forcing Xiongnu to take her hands off the Western Regions. The Han dynasty took an absolute control of the Western Regions. The Xiongnu power was substantially weakened and had no extra power to trouble the Han dynasty anymore.
