Xiongnu
The Xiongnu () were a confederation of nomadic peoples who, according to ancient Chinese sources, inhabited the eastern Asian Steppe from the 3rd century BC to the late 1st century AD. Chinese sources report that Modu Chanyu, the supreme leader after 209 BC, founded the Xiongnu Empire.
Su Wu
In 100 BC, there was a short-lived détente between long-term adversaries the Han and the Xiongnu. One year earlier, in 101 BC, a new chanyu had come to power in Xiongnu, Chanyu Qiedihou (且鞮侯), who had expressed an interest in peace with the Han and who, as a goodwill gesture, had allowed some Han diplomats who had been detained by the Xiongnu to return to Han, along with gifts from the chanyu.