In fact, during the reign of Tang Xuanzong Li Longji, he used three era names, namely Xiantian, Kaiyuan and Tianbao, but although Li Longji sat as emperor during the Xiantian period, he did not really pro-government, and this period lasted relatively short, so the era number of Tiantian was not very well known, on the contrary, the Anshi rebellion during the Kaiyuan prosperous era and the Tianbao years was well known to the world, and these two era names were also widely circulated.
During the Tang Dynasty, there were no regulations on how many era names an emperor had, and some only had one, such as Tang Gaozu Li Yuan's Wude and Tang Taizong Li Shimin's Zhenguan, but in the Tang Gaozong Li Zhi period, there were many era names, and Li Zhi and Wu Zetian were very fond of changing the year number, and they changed it at every turn. Li Zhi changed 14 era names in more than thirty years, Wu Zetian preferred to toss, and changed 14 in the sixteen years of being emperor, plus 4 in the previous regency period, that is, 18 era names in twenty-one years, this frequency is also no one, sometimes an era number can not be changed in a year.
In fact, under normal circumstances, changing the era name is generally when he first sat on the emperor's throne, and when the heavens descended auspiciously or when natural disasters, man-made disasters, and turmoil occurred. Let's take a look at these three era names of Tang Xuanzong:
In 710, Li Longji and Princess Tianping jointly launched the TangLong Coup, purging Wei Hou's party, and then assisting Li Dan in restoring the throne, and Li Long's gene surpassed Li Xian to become crown prince. Next is the brother-in-law fighting method of Li Longji and Princess Taiping, and Li Dan is in the middle of the dilemma.
In 712, the comet crossed, and in addition to the old Buxin, Li Dan gave way to Li Longji and became the Emperor Taishang himself. Li Longji succeeded to the throne and changed his era name to Xiantian, but Li Longji was not fully pro-government, and Li Dan still held the power to appoint and dismiss officials of the imperial court and the power to adjudicate major cases. Li Longji was constrained, and Princess Taiping pressed forward step by step, and finally in 713, before Princess Tianping struck, Li Longji took the lead in attacking and killed Princess Taiping. Li Dan handed over all his power.
Since then, Li Longji has truly pro-government, changed the era name to Kaiyuan, swept away the old weather, and opened a new era.
After nearly a decade of civil strife, Datang finally ended here with Li Longji. After that, Li Longji made great efforts to govern, reformed internal affairs, and appointed good ministers to bring the Tang Dynasty to the most prosperous Kaiyuan prosperous era. Prosperous Chang'an was born in this period, Li Longji naturally has reason to be proud, nearly thirty years of diligent government and love for the people, he believes that he should do everything in his life, and then it should be time to enjoy.
741 is a relatively special year for Li Longji, in this year, the grand goals he himself set have been achieved, the country is rich and the people are strong, and the 57-year-old feels that his pace should slow down a little, and he should enjoy the pleasure of power instead of continuing to fight. Moreover, in this year, he had two older brothers who died one after another, one of which was Li Shouli, the son of Li Xian, the prince of Zhanghuai, who was Li Longji's cousin, and the other was Li Longji's brother Li Xian. This made Li Longji, who began to enter the old age, feel a lot of emotions.
So on the first day of the first lunar month in 742, Li Longji ordered that the year name be changed to Tianbao.
Li Longji during the Tianbao period was really very different from the past, handling political affairs in general, and doing a lot of confusing things, such as designing his daughter-in-law Yang Yuhuan as his own noble concubine, and later favoring Yang Yuhuan's brother Yang Guozhong. The prosperity of Datang has only existed for a few years and began to decline.
Soon, the time was 755, and in the winter of that year, An Lushan dragged his fat body to rebel. The Anshi Rebellion completely made the prosperity of the Tang Dynasty a thing of the past.
In June 756, when an Anshi rebel army captured Tongguan and saw that Chang'an was about to fall, Li Longji fled with Yang Guifei to Yang Guozhong's hometown in Sichuan, but when he reached Ma Songyi, the soldiers mutinied, and the Yang brothers and sisters lost their lives. Li Longji also became emperor of Taishang passively shortly after, hiding in Sichuan and waiting for his son to quell the Anshi rebellion before taking him back to Chang'an.
Li Longji, who was no longer an emperor, could be said to have lived a very depressed life in the last few years, being put under house arrest by his son and being bullied by eunuchs. He died tragically in 762.