When the fate of Sui Dynasty was coming to an end, Li Shimin secretly planned an uprising. He often lowered his position, respected the scholars, offered his property to support his public, and encouraged his father Li Yuan to fight against the Sui Dynasty, which was called "Jinyang War" in history. Later, the Duke Zen of Sui Dynasty was located in Li Yuan, and the title was changed to Tang, making him a minister. Li Shimin made great achievements in the establishment of the Tang Dynasty. He was powerful and ambitious, but he was not the eldest son. Finally ascended the throne because of the change of Xuanwu. It was not until the mutiny that he saw that his sons were incompatible with each other and decided to let Li succeed in Guanzhong. Li Shimin was unwilling, so he joined his generals to set up a heavy army at Xuanwu Gate, ambushed and killed Prince Li Chengjian and Li Yuanji, the king of Qi who came to appear before the court, and at the same time wiped out the forces of the Prince. After the death of the Prince, Tang Gaozu had no choice but to make Li Shimin the Prince, and all kinds of government affairs were decided by Li Shimin. A few months later, Tang Gaozu was forced to step down by Li Shimin and became an emperor in name only. Li Shimin finally ascended the throne.
3. Li Shimin's successor is cheap, knowing people and making good use of them; Speak freely, respect life, exercise self-restraint, and be open-minded to teach; And adopted policies such as taking agriculture as the foundation, practicing economy, recuperating, reviving culture and education, and perfecting the imperial examination system to stabilize the society; And vigorously pacify foreign aggression, respect border ethnic customs, stabilize the border areas, and finally achieve the ideal situation of governing the world. The rule of Zhenguan laid an important foundation for the prosperity of Kaiyuan and pushed China's traditional agricultural society to its peak.