李元吉
Eventually, Li Shimin submitted a message to his father, Emperor Gaozu, accusing Li Jiancheng and Li Yuanji of having illicit affairs with several consorts of the emperor. After receiving the message, Emperor Gaozu summoned Li Shimin to come for an audience the following morning. The emperor also requested for his personal advisors Pei Ji, Xiao Yu, Chen Shuda, Feng Lun, and Yan Shigu to come. However, Consort Zhang () learned of Li Shimin's accusations and informed Li Jiancheng. Li Jiancheng summoned Li Yuanji to deliberate together on how to deal with the difficult situation. Li Yuanji opted to not attend the imperial court that morning, but to excuse themselves due to "illness" and prepare the troops, so they could observe the situation. However, Li Jiancheng said that the troops were already prepared and wanted to leave for the Palace City to hear first-hand what was amiss. While Li Jiancheng and Li Yuanji left at dawn to consult Emperor Gaozu personally, Li Shimin and his followers had taken control over Xuanwu Gate.