During the period of Emperor Wu of the Western Han Dynasty, the national strength was at its peak. On the one hand, he sent Li Guang and other famous soldiers to attack the Xiongnu, on the other hand, he sent envoys to the Western Regions to weaken the influence of the Xiongnu in the Western Regions. Emperor Wu sent Zhang Qian to Shanshan, Gaochang, Loulan and other countries. In an extremely difficult and dangerous environment, Zhang Qian planned to kill the Xiongnu emissary. He was active in the Western Regions for more than 30 years and made great contributions to strengthening the ties between the countries in the Western Regions and the Han Dynasty. After Zhang Qian returned to the Han Dynasty, he was made a "prince" for his meritorious service.
Zhang Qian made such a great contribution to the Western Regions that later generations deified him. Legend has it that Emperor Wu of the Han Dynasty sent Zhang Qian to find the source of the Yellow River, and Zhang Qian went upstream on a raft. After a long time, he passed through a deserted area and arrived at a densely populated market town, where men plowed and women weaved in an orderly way. He walked into a house and saw the mistress of the house weaving and her husband drinking water with her cow. Zhang Qian was surprised and asked them, "What is this place?"
The host pointed to the river where the cows drank water and said, "This is Tianhe." The hostess gave Zhang Qian a stone to support the loom. After Zhang Qian brought it back, Dong Fangshuo, who was well informed, recognized that it was a stone stuffed under the weaver loom in the sky.
Later, people used the allusion "Zhang Qian rode in a chariot" to describe the messenger's long journey.