Why did Li Shimin let Wei Chijingde kill Fang Lingxuan and Du Ruhui on the eve of the Xuanwu Gate Rebellion?

On the eve of the Xuanwumen Uprising, Li Shimin asked Wei Chijingde to take up his sword and kill Fang and Du Ruhui. As we all know, Fang and Du Ruhui synthesized "Fang Mou Du Duan", which was not only the founding hero of the Tang Dynasty, but also a famous figure in the Tang Dynasty, and made great contributions to the creation and prosperity of the Tang Dynasty. In addition, they are close friends of Emperor Taizong and Li Shimin. Li Shimin wanted to kill them because of a misunderstanding.

First, the relationship between Fang and Du Ruhui.

During the founding war of the Tang Dynasty, Fang and Du Ruhui joined early and became the best among the "Eighteen Bachelor of Qin". Fang and Du Ruhui are the brains and strategists that they often take with them when they are in the Quartet.

Their position and close relationship in Li Shimin's mind can be seen from the ranking of the top 20 in Lingyange. Du Ruhui ranked third and Fang ranked fifth. Among the top five, they all occupied a place, and Li Jing, who laid half of the country for the Tang Dynasty, ranked eighth. It can be seen that their relationship with Li Shimin is extraordinary.

Second, why kill Fang Du Ruhui?

The cause of the incident was a misunderstanding. Before the change of Xuanwu Gate, the prince was ready to attack Li Shimin. Li's advisers and military commanders were gradually transferred from Beijing to other places under various pretexts to divide their forces. Fang and Du Ruhui, as the right-hand man, Li Ziran let them go, saying that they were expelled from Beijing and were not allowed to enter Beijing without imperial edict.

Seeing the urgency of the situation, it is always difficult to make up his mind. He has been hesitant to put all his eggs in one basket with Li. On the eve of the Xuanwu Gate Rebellion, they wanted to recall Du Ruhui and discuss countermeasures, while Fang and Du Ruhui made excuses to force them to make a decision as soon as possible.

Li Shimin flew into a rage and misunderstood Du Fang's idea that they would betray themselves. This ordered Wei Chijingde: "Let's go on and see if there is a heart, but the first one can be beheaded." Holding a sword, he killed Fang and Du Ruhui. Wei Chijingde and Fang Du Ruhui knew that they had made up their minds, so they rushed to the Qin Palace and made a comprehensive plan for the change of Xuanwu Gate.