Zhang Qian
Zhang Qian was born in Chenggu (the present Chenggu County of Shaanxi Province) of Western Han Dynasty (206 BC-24 AD). He was an outstanding envoy and explorer in Chinese history, opening up the ancient Silk Road and bringing reliable information about the Western Regions.
During the reign of the Emperor Wudi of the Han Dynasty (206 BC-220 AD), the Huns (Xiongnu) often intruded into the northern borders of the Han Empire, so the emperor was making preparations to fight against the Huns. When he knew Da Yuezhi (an ancient state in Amu Darya) had a feud with the Huns, because its king was killed by the Huns' Chanyu (the headman of Hunnish tribes) and the head made into a goblet, he decided to unite with this state to combat their common enemy. Therefore, Zhang Qian was sent as a diplomatic envoy to the Western Regions.
In 139 BC, with about 100 people, Zhang Qian departed from Longxi (in Gansu Province). Unfortunately, he and the delegation were captured by the Huns when they reached the Hexi Corridor and detained for ten years as hostage. Finally, they found a chance to flee. They crossed deserts and the Gobi, and went over the snow-covered Pamirs. After about ten days, they arrived in Dawan (in Fergana Basin). Under the help of a Dawan's guide, they went through Kangju (between Balkhash Lake and the Aral Sea) and reached Da Yuezhi.
To Zhang's surprise, satisfied with their life, the Da Yuezhi people refused to make an alliance against the Huns. Besides, they thought it was impossible to resist the Huns together because they were far away from the Han Dynasty. Zhang Qian made an on-the-spot investigation in Daxia (Balkh) and other countries for more than one year. In 128 BC, He decided to return to Chang'an (the ancient name of Xi'an). On their return journey, they were captured by the Huns again and detained for more than one year. In 126 BC, Zhang seized the opportunity provided by internal disorder among the Huns. He escaped and reached Chang'an. Although he failed to finish the mission to make a military alliance with Da Yuezhi, he obtained a great deal of knowledge about the people, geography, culture and customs of 36 states in the Western Regions.
In 119 BC, Zhang Qian set off on his second journey to the Western Regions, in order to ally with Wusun (in Ili) Valley) against the Huns. At that time, the Huns had been expelled from the Hexi Corridor, so Zhang Qian reached Wusun easily. Then he sent other envoys to Dawan, Kangju, Da Yuezhi, Anxi (Parthia, in now Iran), Juandu (present India), Yutian (Hetian) and other countries. In 115 BC, the king of Wusun put an interpreter and a guide at Zhang's disposal. Moreover, Wusun's ten envoys convoyed Zhang to Chang'an. He died there in 114 BC. Then the diplomatic envoys he sent came back in droves. Finally, the Han Dynasty was able to build good relationships with states of the Western Regions.
Further Reading:
Tomb of Zhang Qian in Hanzhong, Shaanxi Silk Road in Western Han Dynasty