杜如晦
Some canonical texts have asserted that prior to the coup, Prince Li Shimin survived a poisoning attempt by his two brothers. According to the "Jiu Tangshu", it happened prior to 626, while the "Zizhi Tongjian" dates it to the 6th lunar month of 626, placing it within three days of the coup. states that the latter interpretation is most probably the one to be incorrect, since the poisoning had rendered Li Shimin seriously ill. It is still disputed when or whether this poisoning actually happened. Crown Prince Li Jiancheng and Prince Li Yuanji successfully plotted the dismissal of Fang Xuanling and Du Ruhui, Li Shimin's principal advisors, from service. Li Shimin's general Yuchi Jingde escaped an assassination attempt ordered by the two princes, but he was later slandered by the two princes at court and came near execution if it had not been for Li Shimin's intercession. By 626, Li Shimin became increasingly worried by his brothers' successful machinations in turning Emperor Gaozu against him and in removing his staff members.