What is historical regret?
In the first year of Zhenguan, he was granted the title of crown prince, but he was ultimately unable to become emperor.
It was the sudden leg disease in the ninth year of Zhenguan, and the pressure from all sides caused a drastic change in temperament.
In the 16th year of Zhenguan, he was forced to rebel and was demoted to a commoner.
He died in Qianzhou in the 19th year of Zhenguan, and was lost in the long river of history.
If none of this happened, then...
