Feng Ba
In 414, Emperor Mingyuan sent ambassadors to Later Qin, Northern Yan, Jin, and Rouran, to try to establish peaceful relationships. The Later Qin and Jin missions were apparently largely successful, but his ambassador Huniuyu Shimen (忽忸于什門) had a conflict with the Northern Yan emperor Feng Ba over Feng Ba's insistence that Huniuyu kneel to him, and Feng Ba detained Huniuyu and refused to establish relations with Northern Wei. How successful the Rouran mission was is harder to gauge, for although initially it appeared to be successful, by new year 415 the Rouran Khan Yujiulü Datan (郁久閭大檀) invaded, and Emperor Mingyuan was forced to respond, chasing Yujiulü Datan back to his territory, but when Emperor Mingyuan sent his advisor Daxi Jin (達奚斤) to pursue Yujiulü Datan, the Northern Wei forces ran into severe weather and suffered many casualties based on frostbite. This would start a theme that would last for centuries—often, Rouran would attack, and Northern Wei would counter-attack successfully, but then become unable to have decisive victories over Rouran.