In 676, when the Tibetan Empire attacked Tang's western prefectures, Tang prince Li Xiǎn and his younger brother Li Lun, the Prince of Xiang, were nominally put in charge of the two armies that were actually commanded by the generals Liu Shenli (劉審禮) and Qibi Heli (契苾何力), but neither Li Xiǎn nor Li Lun actually set out with the troops.