Objectively speaking, Li Shimin has made great contributions. There is no doubt that Li Shimin has the ability to respect this noble corporal and accept training with an open mind. During his 23 years in office, he created a prosperous time of Zhenguan with thunderous momentum, which fully proved his extraordinary talent. In the Tang Dynasty, it took seven years from the reign of Li Yuan in 6 18 to the unification of the whole country in 624. Li Yuan played a decisive role from the start of the army to the establishment of Chang 'an City, but all these important tasks were completed under the leadership of Li Shimin.