Dayuan (大宛) was an ancient country in modern-day Fergana of the Middle Asia. This country had a kind of famous horse which was called “blood-sweat horse” (汗血马), because the sweat of this kind of horse looks like blood. In the history, there were two wars for the “blood-sweat horse”.
When the envoys of the Western Han Empire came to Dayuan and found the strong horses, they reported to their emperor, Han Wu-Emperor (汉武帝). At that time, the Han Empire fought against the Huns, and needed many strong horses to equip the cavalry. When Han Wu-Emperor heard the message, he felt very excited, and sent envoys to take a gold horse and much gold to exchange blood-sweat horses. The king of Dayuan coveted the treasures of the Han Empire, but he thought his country was very far from the Han Empire, so it wasn’t necessary to be worried about the army of Han. Then the king of Dayuan refused to give horses to Han’s envoys. Han’s envoys were very angry. They spoke rudely, and broke the gold horse. Dayuan’s king was shamed into anger, and instigated the king of Yucheng (郁成) which was his neighbouring country to attack Han’s envoys. The envoys were killed and their treasures were grabbed.
The news shocked the Han Empire. The emperor decided to punish Dayuan. Because Loulan (楼兰) which was an ancient country in modern-day Xinjiang of China were seized by seven hundred cavalrymen, the ministers thought three thousand armymen were able to seize Dayuan by strong crossbows. Han Wu-Emperor underestimated Dayuan, too. He sent Li Guangli (李广利) who was the brother of his loved concubine to command six thousand cavalrymen and several ten thousand armymen who were enlisted from ruffian boys to start an anabasis. In 104 B.C., the first war of Dayuan was started.
In the very long march of deserts, the underestimate for the conditions brought serious sufferings to the Han’s army. Their foods were exhausted soon. The countries along the way refused to supply foods to Han’s army, because they were worried that the Han’s army had malicious intentions. The army of China was called “the army of propriety and justice” (礼义之師), but when the army was mired in difficulties, they could do any thing. Han’s armymen had to attack the countries along the way. When they captured a city, they plundered in the whole city and got supplies which could be kept in several days. If they couldn’t capture a city, they had to leave. When the Han’s army arrived at Yucheng, only several thousand armymen remained in this army. They attacked Yucheng, but they were defeated seriously. Li Guangli thought his army hadn’t been able to attack Dayuan, so he led his army to return.
When the army returned Dunhuang (敦煌) where was in the border, only about ten percent of armymen survived. Han Wu-Emperor was filled with fury, and sent envoys to tell Li Guangli, “Any armyman who dares to enter Yumen Pass (玉门关) will be killed at once.” Li Guangli feared, and led his army to stay at Dunhuang.
Han Wu-Emperor thought if his empire couldn’t punish Dayuan, foreign countries would look down on his empire. So he decided to try all best to seize Dayuan. He pardoned criminals, and enlisted them and ruffian boys into the expeditionary force. Many well-trained cavalrymen joined in the army. A year later, the expeditionary force had sixty thousand armymen, a hundred thousand cattle, thirty thousand horses and ten thousand other transportation animals. The army prepared ample foods and enough crossbows. In addition, many common people volunteered for the army by their own foods, weapons and accoutrements. The fully prepared army was led by more than fifty military officers whose rank was "Xiaowei"(校尉, the rank was only second to a general). Han Wu-Emperor heard that there weren't water wells in the Dayuan city and the Dayuan people depended on a river outside the city as the only water source, so he let many water engineers follow the army for cutting off the water source of the Dayuan city. For guarding against the Huns, Han Wu-Emperor sent one hundred and eighty thousand armymen to garrison the northwestern border.
In 102 B.C., there was the second war of Dayuan. Li Guangli was still the commander. Now his army was very strong and had enough supplies. So the most countries along the way hospitably treated the Han’s army. But a country named Luntou (仑头) refused to accommodate the Han’s army, and then the Han’s army captured the capital of Luntou and destroyed this city.
When the Han’s army arrived in Dayuan, they met the army of Dayuan. They defeated the Dayuan's army by their strong crossbows. At that time, the crossbows of the Han Empire were very powerful weapons. The army of Dayuan had to retreat and hold their city. The Han’s army cut off the water source of the Dayuan city. Though the Dayuan people were mired in difficulties, they still uncompromisingly resisted the Han's army. The Dayuan city was besieged. About forty days later, the outer city-wall of the Dayuan city was broken, and a brave general of Dayuan was captured. The army and people of Dayuan still held the central part of this city.
The nobles of Dayuan started to be in a serious panic. They thought the cause of the war was that their king killed Han’s envoys and refused to give horses to Han. So they killed their king and sent a noble to give the king’s head to Li Guangli and told him, “Please not attack us. We will show all of our good horses, and you can take any one which you like. And we will give supplies to you. But if you don’t agree, we will kill all of our good horses at once, and Kangju (康居) will aid us. If they arrive, we are inside, and they will be outside, if the armies of our two countries attack the Han’s army at the same time, how can you do?” Kangju was an ancient strong country in modern-day Samarkand, Uzbekistan. The Kangju's army had already arrived in Dayuan, but they thought the Han’s army was strong, so they didn’t dare to attack.
Li Guangli and other officers thought that, if they didn’t agree with the nobles of Dayuan, the Dayuan people would desperately defend their country, and the battles would exhaust the Han’s army. If the Kangju’s army takes the chance to attack the Han’s army, the Han’s army would be defeated. So Li Guangli promised the nobles of Dayuan. The nobles of Dayuan gave many supplies and showed their good horses to the Han’s army. The armymen of the Han Empire chose tens of the best horses and about three thousand middling horses as captures. The Han’s army let Mose (昧蔡), a noble of Dayuan, who once treated Han’s envoys friendly, become the king of Dayuan. They signed a treaty with Mose, and then left Dayuan.
The Han’s army broke the Yucheng city, and the king of Yucheng ran away to Kangju. The king of Kangju heard the news that Dayuan had surrendered, so he gave the king of Yucheng to the Han’s army. The king of Yucheng was killed by a young cavalryman.
Han Wu-Emperor once demanded Wusun (乌孙, an ancient strong country which was built by the ancestors of Kazak) to send a strong force to support the Han’s army. Wusun sent two thousand cavalrymen, but these armymen didn’t want to offend Dayuan. So they didn’t attack Dayuan. After Dayuan surrendered itself to the Han’s army, Wusun and many countries treated the armymen of the Han Empire very respectfully. They sent the children who were from noble families to present treasures and serve the emperor of Han Empire.
A year later, the nobles of Dayuan thought that Mose was a sycophant and many people of Dayuan were slaughtered because of his sycophancy. So they killed Mose, and let another noble become the king. They didn’t want to offend the Han Empire, so they sent the son of the new king to the Han Empire and serve the emperor of Han.
Since then, in the Middle Asia, there wasn’t a country who dared to offend the Han Empire. The first war of Dayuan showed that, though the Han Empire called herself “the land of propriety and righteousness” (礼义之邦), the armymen of the Han Empire still dared to do any thing what they wanted to do. The second war of Dayuan showed that, the Han Empire was able to punish any remote country. The envoys and traders from the Han Empire were treated friendly and respectfully. Many armymen of the Han Empire garrisoned many countries which were in modern-day Xinjiang, and helped them to guard against the Huns.
Since then, the Silk Road was protected completely by the Han Empire, and the Han Empire built the hegemony in the Middle Asia. If the king of any country didn’t obey the Han Empire, he would be eliminated. Even if the envoys of the Han Empire thought a king wasn’t deferential to their nation, they dared to assassinate him without the order of the imperial government. The women who were sent to marry with the kings of the countries were loyal to their motherland. When Han’s envoys arrived, the women would report all intelligence to their compatriots.
As an officer of the Han Empire said proudly in 36 B.C., “If someone dares to offend the great Han Empire, even though he is in a remote country, he will be punished.”