Ashina Helu
In 655 as well, Emperor Gaozong commissioned the general Cheng Zhijie () to attack Ashina Helu, but while the campaign saw some victories over Western Turkic Khaganate's substituent tribes Geluolu () and Chuyue (), it was hindered by Cheng's inability to restrain his assistant Wang Wendu () from pillaging and inappropriately halting the army. After the campaign ended in early 657, both Cheng and Wang were deposed from their offices.