Zhang Qian in ancient China is regarded as "the first Chinese stepping to the world". In 138 B.C., Zhang Qian went on a mission to the Western Regions. In his travel, he was captured by the tribe of Xiongnu and forced to stay in the Xiongnu Region for more than ten years. During this period, he was waiting for a chance to get back to his motherland. In the end, Zhang Qian managed to go back to Chang'an, the capital of the Western Han Dynasty, in 126 B.C. Thanks to his exprience, Zhang Qian had a detailed knowledge of the geography, products and customs of the Western Regions, providing precious information for opening up the Silk Road.