Emperor Xuanzong of Tang - During Emperor Ruizong's Second Reign

During Emperor Ruizong's Second Reign

Emperor Ruizong was immediately faced with the issue of whom to make crown prince—as Li Chengqi, as the oldest son overall and the oldest son of his wife, was the appropriate heir under Confucian principles of succession, but Li Longji had been the one whose accomplishments had allowed him to retake the throne. He hesitated. Li Chengqi declined consideration to be crown prince—stating to his father:

If the state were secure, then consideration should be first given to the oldest son of the wife. If the state were in danger, then consideration should be first given for achievement. If you did not follow this principle, the people of the entire empire will be disappointed. I would rather die than to be placed above the Prince of Ping .

Li Chengqi wept and begged to yield for several days, and after further persuasion by the chancellor Liu Youqiu—who had been part of Li Longji's coup plans—Emperor Ruizong agreed, and created Li Longji crown prince. Li Longji submitted a petition offering to yield to Li Chengqi, but Emperor Ruizong rejected it.

Initially, Princess Taiping agreed to Li Longji's ascension as crown prince despite the fact that Li Longji was not Emperor Ruizong's oldest son and was not born of Emperor Ruizong's wife Empress Liu (Li Chengqi was both — and therefore pursuant to Confucian principles of succession should have been crown prince) as she believed that Li Longji was young (25 at the time he was made crown prince) and would be easy to control. However, once she began to see that Li Longji was strong-willed, she became apprehensive and often had officials close to her publicly opine that Li Longji was an improper crown prince. She further often paid Li Longji's staff members to spy on him to try to find faults with him. She associated with a group of officials, including the chancellors Dou Huaizhen, Xiao Zhizhong, and Cen Xi, intending to find some way to remove Li Longji, but was unable to get two other chancellors — Wei Anshi and Song Jing — to join her group.

In 711, Song and another chancellor, Yao Yuanzhi, tried to persuade Emperor Ruizong to carry out a plan that they believed would end her plotting. They proposed that the two princes who arguably had superior claims on the throne than Li Longji — Li Chengqi and Li Shouli (whose father Li Xian (note different character than Emperor Zhongzong) was an older brother to both Emperors Zhongzong and Ruizong) — be sent out of the capital Chang'an to serve as prefectural prefects, while Princess Taiping and Wu Youji be sent to live in Luoyang. They also proposed that Li Longji be put in charge of most affairs of state. Emperor Ruizong initially agreed and made the orders as Song and Yao suggested, except that he believed that Luoyang was too far and therefore sent Princess Taiping and Wu Youji only to Pu Prefecture (蒲州, roughly modern Yuncheng, Shanxi). After Princess Taiping found out that the plan was conceived by Song and Yao, however, she was incensed and let Li Longji know her anger. In fear, Li Longji submitted a petition accusing Song and Yao of alienating him from his brothers Li Chengqi and Li Shouli (who was actually a cousin but was raised with Emperor Ruizong's sons) and aunt Princess Taiping, asking that the two be put to death. Emperor Ruizong, in response, demoted Song and Yao and recalled Princess Taiping, Li Chengqi, and Li Shouli to the capital. In the aftermaths, Li Longji submitted another request to yield the crown prince position to Li Chengqi, but Emperor Ruizong declined it. Also in 711, Emperor Ruizong posthumously honored both Empress Liu and Li Longji's mother Consort Dou as empresses and built a temple for them to be worshipped, but was unable to locate their bodies for reburial, and therefore had to give them a ceremonial reburial without the bodies. Emperor Ruizong also ordered that all minor matters be decided by Li Longji.

In 712, Princess Taiping had astrologers warn Emperor Ruizong that the constellation that symbolized the imperial throne, Dizuo (帝座), showed that there would be a change in the emperor's position — believing that Emperor Ruizong would suspect Li Longji of plotting a coup and that she could remove Li Longji this way. Instead, Emperor Ruizong, reasoning that the change in the emperor's position could be accounted by an orderly transition, offered to pass the throne to Li Longji. Princess Taiping fervently opposed it, and Li Longji initially declined, but at Emperor Ruizong's insistence finally accepted and took the throne on 8 September (as Emperor Xuanzong). However, at Princess Taiping's suggestion, Emperor Ruizong retained much of the imperial power as Taishang Huang (retired emperor), and his edicts continued to carry greater force than Emperor Xuanzong's.