War of the Heavenly Horses

A horse of the Later Han Dynasty (1st–2nd century AD)

The Emperor Wu of Han received reports of the tall and powerful horses ("heavenly horses") in the possession of the Dayuan, which were of capital importance to fight the nomad Xiongnu. The refusal of the Dayuan to offer them enough horses along with a series of conflicts and mutual disrespect resulted in the death of the Chinese ambassador and the confiscation of the gold sent as payment for the horses.

In response, the Emperor sent out Li Guangli, the brother of his favorite concubine, with 6,000 horsemen and 20,000 infantry soldiers. Li's army had to cross the Taklamakan Desert and his supplies soon ran out. After a gruesome march of over 1,000 miles he finally arrived to the country of Dayuan, but what remained of his army was exhausted and starving. Li lost many men along the way in petty fights with local rulers. After a severe defeat at a place called Yucheng, Li concluded that he was not strong enough to take the enemy capital and therefore returned to Dunhuang about 102 BC.

Emperor Wudi responded by giving Li Guangli a much larger army along with a huge number of oxen, donkeys and camels to carry supplies. With this force he had no difficulty reaching Khujand (called Ershi 貳師 by the Chinese), the Dayuan capital. He lost half his army during the march, but after a 40-day siege the Chinese had broken through the outer wall and cut off the water supply. The nobles of Ershi killed their king and sent his head to Li Guangli, offering the Chinese all the horses they wanted. Li accepted the offer, appointed one of the nobles to be the new king and withdrew with a tribute of 3,000 horses. On his return journey all the petty states accepted Chinese sovereignty. He reached the Jade Gate about 100 BC with 10,000 men and 1,000 horses.