Su Wu (simplified Chinese: 苏武; traditional Chinese: 蘇武; pinyin: Sū Wǔ; Wade–Giles: Su Wu; 140 BC - 60 BC) was a Chinese diplomat and statesman of the Han Dynasty. He is known in Chinese history for making the best of his mission into foreign territory: where, despite being captured during the event and being detained for nineteen years, enduring major hardship at least in the beginning years of his captivity, he yet endured, all the while remaining faithful to his mission and his homeland. According to Chinese tradition, in the early time of his captivity, Su Wu was so deprived of food that he only survived in the cold north lands by eating his coverings, then enduring long years of servitude herding sheep, before managing to return home, after deceiving his captors with a story about his having sent a message back to China by means of tying a letter on the leg of a wild goose. Sometimes Su's loyalty to the Han Dynasty is emphasised by the story that during his detainment he married a wife, that he had children by her, but that he chose to return to his homeland, even though it meant it abandoning his wife and children.
Not much is known about Su's life or career until his most well known mission beyond the borders of China involving the Xiongnu: a mission which turned out to be drastically more trying and lengthy than expected.
In 100 BC, there was a short-lived détente between long-term adversaries Han and Xiongnu. One year earlier, in 101 BC, there had been a new chanyu who came into power in Xiongnu—Chanyu Qiedihou (且鞮侯), who had expressed interest in peace with Han and who, as a goodwill gesture, had allowed some Han diplomats who had been detained by Xiongnu to return to Han, along with gifts from the chanyu.
In response, in 100 BC, Emperor Wu of Han commissioned Su, then the deputy commander of the imperial guards, to serve as an ambassador to Xiongnu. His deputy was fellow deputy commander Zhang Sheng (張勝), and the third in command was Chang Hui (常惠). However, once they arrived at the Xiongnu chanyu's headquarters, Chanyu Qiedihou was far more arrogant than expected, which angered Zhang. In response, Zhang plotted with two Xiongnu officials, the Prince of Gou (緱王) and Yu Chang (虞常), to assassinate Chanyu Qiedihou's half-Chinese advisor Wei Lü (衛律) and kidnap the chanyu's mother.