Floor: 1 [Analysis of ideas] Emperor Taizong first made his eldest son Li Chenggan a prince, and then he doted on the four sons. Li Chenggan was afraid of losing his heir and attempted to launch a coup to assassinate Lee Tae. This was unsuccessful and was abolished as Shu Ren. In order to prevent the tragedy of brother's vendetta, Emperor Taizong demoted Wang Wei and Lee Tae, and changed his ninth son, Jin Wang Li Zhi, to be the Prince, which is the future Tang Gaozong.

In his later years, Emperor Taizong wrote a book "Emperor Fan" to teach the prince, which summarized his political experience all his life and commented on his own merits and demerits. In the twenty-third year of Zhenguan, Emperor Taizong was critically ill, and Sun Chang Wuji and Chu Suiliang assisted Li Zhi behind him. Buried in Zhaoling after death.

1, Li Zhi, born of the eldest grandson, is a direct descendant and has a moral advantage.

2. Li Zhi didn't participate in the complicated and dirty court political struggle, and was born innocent (in the history of China, it is not easy to find a prince with an innocent birth).