 They were ordered to attack Wagang Fort, but they failed and then surrendered to the rebellion army.Later, Pei Xingyan became one of the four major cavalry officers in Wagang Fort.After the rebellion of Wagang Fort eventually ended with internal conflicts, Pei, along with Cheng Yaojin and Qin Shubao (See Below), joined another rebellion army led by warlord Wang Shichong (王世充).