The prosperous Kaiyuan Reign Period was created by Li Longji, Emperor Xuanzong of the Tang Dynasty (618-907).

In 712, Li ascended the throne, and won the fight against Princess Taiping for the royal court. The 27-year-old quickly consolidated his rule and revitalized the royal court, showcasing his extraordinary courage.

Li ruled the state with the integration of punishment and moralization. He dismissed greedy officials and appointed outstanding talents. He was active, emphasizing the laws, but not completely following the previous ones.

He brought back the prosperity of the Zhenguan Reign Period (Zhen Guan Zhi Zhi), which was created by his great-grandfather, Emperor Taizong Li Shimin.

From 742 to 755 during his reign, the national population exceeded 50 million, which was equal to that of the Mediterranean in the 16th century. The farmland at that time covered an area of 660 million mu (44 million hectares), with over nine mu per capita.

The total number of vassal states that presented tributes to the royal court was up to 70 during that period. Businessmen gathered in the state and overseas students came for further study.

Cultural education was also booming and reading was popular among the public. The number of descriptions reached 53,915, and that of books written by scholars of the Tang Dynasty amounted to 28,469.

In addition, the government advocated education, setting up many public and private schools. In 738, Emperor Xuanzong commanded that schools should be established in all townships, contributing to the community from the old to the young.