In spring 565, Emperor Wu sent his brother Yuwen Chun () the Duke of Chen, Yuwen Gui () the Duke of Xu, Dou Yi () the Duke of Shenwu, and Yang Jian (楊薦, different person than the more-known Yang Jian, referenced above and below) the Duke of Nanyang, to lead a ceremonial guard corps to Tujue to welcome back Ashina Qijin's daughter for marriage to him. However, when they arrived at Ashina Qijin's headquarters, he turned against the treaty and detained Yuwen Chun and his attendants.