As the founder of the Kaiyuan prosperous era, Tang Xuanzong Li Longji left a glorious mark in history, but what is less known is that according to the patriarchal inheritance system, Li Long basically did not have the opportunity to become an emperor.
Since the Zhou Dynasty, in order to ensure the smooth transfer of power, the ancient dynasty has formulated a set of rules from the identity and bloodline, that is, the so-called "there is a concubine, no concubine", the eldest son is the first heir to the throne, followed by the second son, the third son, etc., if there is no concubine, it will be the turn of the eldest son. Tang Ruizong Li Dan had a total of six sons, Li Chengqi was the eldest son, as early as the age of six years was crown prince, the history books record that he was talented when he was young, especially proficient in music, has a unique insight into the Western Guizi movement, and Li Longji is the third son and is still out, why did Li Dan pass the throne to Li Longji in the end?
In 683, Emperor Gaozong of Tang died, leaving behind a testament that "Crown Prince Li Xian ascended the throne before the coffin, and those who could not adjudicate major military affairs were decided by the Queen of Heaven (Wu Zetian)", on the one hand, it was clearly stated that Li Xian succeeded to the throne, and on the other hand, wu Zetian was given the right to listen to the government.
The following year, Li Xian was preparing to promote his father-in-law Wei Xuanzhen to be a servant, but was stopped by the chancellor Pei Yan, so he angrily said, "Even if you give the whole world to Wei Xuanzhen, why can't you?" Do you still care about a waiter? The emperor who was angry with the crown was certainly not a good emperor and could not maintain the Tang Dynasty, so Wu Zetian deposed Li Xian as the King of Luling and instead established his fourth son Li Dan the Prince of Yu as emperor, known in history as "Tang Ruizong", and Wu Zetian continued to reign in the dynasty.
At the beginning of Li Dan's succession, he crowned li Chengqi, the eldest son of the six-year-old concubine, as crown prince. However, Wu Zetian was ambitious, Li Dan only served as emperor for six years, he was forced to cede the imperial throne to his mother, in 690 Wu Zetian was called emperor, Li Dan was demoted to imperial heir, moved to the Eastern Palace, all etiquette was compared to the specifications of the crown prince, and the crown prince Li Chengqi was demoted to imperial grandson. Although Li Dan was comparable to the crown prince, he was once attacked by Wu Zetian's cool officials and henchmen, and even because he was falsely accused of rebellion, the subordinates of the Eastern Palace were severely tortured by the cool officials Lai Junchen, and finally because of the music worker An Jinzang's public dissection, to show that Li Dan did not rebel, Wu Zetian no longer suspected, and Li Dan escaped the disaster.
In 698, after wu Zetian had been emperor for eight years, under the persuasion of Di Renjie, Wang Fangqing and other ministers, he decided to return power to Li Shi, and took Li Xian, the king of Luling, back to Luoyang. Li Dan, who had long been related, immediately claimed that he was ill and did not go to the dynasty, and wrote to give up the position of crown prince to Li Xian, in order to escape the political whirlpool, so Li Xian became the crown prince again.
In 705, Zhang Kamzhi and others launched the Shenlong Coup and forced Wu Zetian to pass the throne to Li Xian, and Li Xian became emperor again, known as "Emperor Zhongzong of Tang" in history, and crowned Li Chongjun as crown prince. However, although Wu Zetian, the "Great Demon King", was removed, it may be that Wu Zetian had made a bad start, so that the concubines in the palace were not willing to be lonely, and Tang Zhongzong's empress Wei Shi also wanted to become the second Wu Zetian, so the palace coup was staged again and again.
After Li Xian became emperor, he was very conniving with his wife Wei Shi, who was suffering and sharing, so the government was gradually controlled by the Wei Hou clan, and Wei Hou's henchmen wantonly suppressed Zhang Kamzhi and other forces, resulting in many contradictions within the imperial court. Since the crown prince Li Chongjun was not a child of Empress Wei, Li Chongjun became one of the targets of Wei Hou's party, and li Chongjun was forced to launch a mutiny and kill Wu Sansi's father and son, but under the command of Emperor Li Xian, Li Chongjun was defeated and killed.
Wu Sansi and Li Chongjun died one after another, but instead made Wei Hou more powerful, and Wei Hou at this time was like Wu Zetian at that time. In June 710, Emperor Zhongzong of Tang suddenly died violently, and Empress Wei supported Li Xian's younger son Li Chongmao to ascend the throne, and he himself took over the throne, monopolizing power, and the imperial court was densely packed with henchmen, and Wei Hou once planned to claim the title of emperor, of course, there were many people who opposed Wei Hou.
At this time, the other Li Tang imperial families may still be safer, while Li Dan, who was once emperor, and Li Chengqi, the crown prince, are in extreme danger, and Wei Hou is likely to find an opportunity to get rid of them to avoid future troubles. But these two people did not do anything, just went with the flow, while Li Longji, who was 18,000 miles away from the throne, was planning a coup d'état.
Li Longji was Li Dan's third son, his mother was Dou Defei, he was crowned King of Chu two years after his birth, and later wu Zetian succeeded Li Hong (the eldest son of Wu Zetian and Li Zhi) as a son, following his incense, in 693 Empress Liu (Li Chengqi's mother) and Dou Defei were accused of cursing Wu Zetian and were killed, so the 9-year-old Li Longji was demoted by Wu Zetian to the prince of Linzi and was placed under house arrest for 7 years. During the Wu Zetian period, Li Longji served as the right guard general of the Imperial Guard, and later served as shangren fengyu, responsible for the emperor's internal and external stables and horses, and never had much power. In Li Xian's time, Li Longji served as a luzhou driver and had little power.
In 710, the 26-year-old Li Longji returned to Chang'an from Luzhou, immediately allied with Princess Taiping, united the anti-Wei forces, and secretly gathered brave warriors to plot to restore the Tang Dynasty, and in just a few months, he successfully launched the Tanglong coup, killing Wei Hou, Princess Anle, Shangguan Wan'er, etc. with the rebellious forbidden army, and completely destroying the Wei clique. It can be said that when he was young, Li Longji was amazingly talented, his politics and strategy were first-class, he was a true son of natural choice, and he almost single-handedly reversed the situation, far more adapted to the situation than his father Li Dan and his eldest brother Li Chengqi.
Contrary to Li Longji, Li Dan and Li Chengqi almost won lying down, neither of them did anything, but one became the emperor and the other became the biggest candidate for the crown prince. The problem is that Li Longji came out of iron blood and could not give up the position of crown prince, so how did Li Longji replace Li Chengji as the crown prince?
After Tang Long's coup d'état, Li Chongmao (Emperor Shao of Tang) could only take the throne, so Li Dan was proclaimed emperor for the second time. The first big trouble that Li Dan encountered was that Li Longji had made great contributions, Li Chengqi was the eldest son of Concubine, both of them had the qualifications to be made crown prince, and whoever was established was suitable, and who was established was unfair to the other, so it was difficult to decide without hesitation.
In the end, Li Chengqi voluntarily resigned from the position of prince on the grounds that "national security is the first to be long-term, and the country is in danger first to have merit". Li Longji certainly could not accept it directly, so he resigned on the grounds that Li Chengqi was the eldest brother, but Li Dan did not accept it, and formally issued an edict to establish Li Longji's position as crown prince.
Two years later, Li Danchan took the position of Li Longji and became emperor taishang. Whether it was during the crown prince or after becoming emperor, Li Longji always gave preferential treatment to Li Chengqi, and finally Li Chengqi died at the age of 63, and Li Longji posthumously called him "Emperor Jean".
The author believes that the reason why Li Chengqi resigned from the position of prince is mainly due to two reasons: on the one hand, in the thirty years since Li Chengqi grew up, the political situation has been turbulent, and becoming a prince may be more dangerous, but it is not as safe as a Taiping prince; on the other hand, Li Chengqi's ambitions are not average, and Li Longji's ambitions are outstanding, if Li Chengqi must become a prince, it is estimated that there is a good chance that the brothers will turn against each other and reproduce the changes in Xuanwumen. Therefore, Li Chengqi's resignation of the position of crown prince is beneficial to himself and li Tangjiangshan, which is a win-win result.
References: New Book of Tang, etc