文档介绍：The Incident at Xuanwu Gate 玄武门之变
Background
Character:
Li Shimin(second son)
Li Jiancheng(crown prince)
Li Yuanji(third son)
Gaozu(emperor)
Site:玄武门(大内皇宫的北宫门)
Time:BC (武德九年六月初四)
唐太宗
李世民
Fuse:Kunmingchi
In summer 626, the Eastern Tujue general Ashina Yushe (阿史那郁设) had entered Tang territory and put Wucheng (乌城, in modern Yulin, Shaanxi) under siege.
Li Shimin, fearful that Li Jiancheng and Li Yuanji would use this opportunity to act against him, decided to act, particularly at the urging of his brother-in-law Zhangsun Wuji(长孙无忌) and
Yuchi Jingde(尉迟敬德).
He had Fang Xuanling(房玄龄) and Du Ruhui(杜如晦) secretly recalled to his mansion(宅邸) to draw the plans for action, and then one night submitted(递交) a secret accusation to Emperor Gaozu(唐高祖), accusing Li Jiancheng and Li Yuanji of affairs with Emperor Gaozu's concubines(妃子) and plans to kill him.
Emperor Gaozu was surprised by the accusation and promised to handle Li Shimin's accusation the next day, and summoned the high level officers Pei Ji, Xiao Yu, and Chen Shuda to prepare to act on the accusations