Zhang Qian 張騫 (d. 114 BCE) was a traveller and discoverer of the mid-Former Han period 前漢 (206 BCE-8 CE).
He hailed from Chenggu 成固 (modern Chenggu 城固, Shaanxi) and became a court attendant (lang 郎) in 140 BCE. In order to check the strength of the steppe federation of the Xiongnu, Emperor Wu 漢武帝 (r. 141-87 BCE) planned to create an alliance with the Tokharians (Chinese name Yuezhi 月氏) that lived in the southern region of modern Uzbekistan. Zhang Qian participated as a voluntary member of the embassy to the Yuezhi.
When the mission crossed the land of the Xiongnu, Zhang Qian was captured and spent more then ten years among them. He even married a native woman but was later able to escape. He travelled westwards into the lands of the Dayuan 大宛 (in the Ferghana Basin, eastern Uzbekistan) and the Kangju 康居 (middle course of the River Syr-Darya in Uzbekistan) before he finally arrived in the land of the Yuezhi. Although the Tokharians had been expelled by the Xiongnu from their former territory, they had meanwhile settled down in the plain between the rivers Amu-Darya and Syr-Darya. They controlled the once mighty empire of Bactria (Chinese name Daxia 大夏) and had no further ambitions to take revenge with the Xiongnu. Disappointed, Zhang Qian spent a full year to visit the country of Bactria and then returned via a southern route in order to avoid the Xiongnu. Yet he was again captured by them and was only able to return when the Xiongnu were preoccupied with internal power struggles, in 126 BCE.
Back in Chang'an 長安 (modern Xi'an 西安, Shaanxi), at the court of Emperor Wu, he gave detailed reports of the western countries and was rewarded with the title of a Superior Grand Master of the Palace (taizhong dafu 太中大夫). During his stay in Bactria he had learned that it was possible to reach this country from China by using the mountain way from Shu 蜀 (modern Sichuan) across India (Chinese name Shendu 身毒). Emperor Wu therefore planned to open the southern route through the territory inhabited by whom Chinese sources call the "southwestern barbarians" (xinanyi 西南夷) of Kunming 昆明, yet this attempt failed. In 123 Zhang Qian took part as commandant (xiaowei 校衛) in Wei Qing's 衛青 campaign against the Xiongnu that ended in a defeat for the steppe federation. Zhang Qian was given the title of Marquis of Bowang 博望侯. He was stripped off this title again in 121 when he commanded a part of another contingent dispatched against the Xiongnu and joined too late with the other divisions.
Zhang Qian suggested to Emperor Wu to forge an alliance with the Wusun 烏孫 against the Xiongu, a people that lived in the Dzunghar Basin. He was appointed leader of court gentlemen (zhonglangjiang 中郎將) and was sent out with 300 men and a rich stock of presents to be given to the Wusun. Arrived in the land of the Wusun, Zhang Qian sent out an official delegation to visit the Dayuan, Kangju, Yuezhi and Bactria. He himself was escorted back by the Wusun and arrived at the Han court in 115 BCE. He died a year later.
Zhang Qian's greatest merit is to have opened the diplomatic and economic communication between Han China and the countries in the west, and so made possible the development of the Silk Road. In the end, the plan to find an ally against the Xiongnu worked out, when the Wusun formally concluded a marriage relationship with the Han dynasty.