Why was Li Chongrun executed after being loved so much What was the true cause of his death

Prince Yide’s name is Li Chongrun, who had a high social status and a worry free life from birth. His real name is Chongzhao, but he changed his name after avoiding martial arts. The legitimate grandson of Emperor Gaozong Li Zhi, the eldest son of Emperor Zhongzong Li Xian, and the mother of Empress Wei.
In January of the second year of Kaiyao (682 AD), Li Chongrun was born in the East Palace Hall. As the only legitimate son of Emperor Zhongzong and Empress Dowager of Tang, in February of the first year of Yongchun (682 AD), Li Chongrun was appointed as the “Crown Prince” while Emperor Gaozu Li Zhishang was still alive. On the day of Li Chongrun’s full moon, Emperor Gaozong of Tang also granted amnesty to the whole country and changed the reign title to Yongchun. This almost indicates that he will inherit the throne in the future. Later, Emperor Gaozong of Tang planned to establish a government office for Li Chongrun and set up officials. However, due to Wang Fangqing, the Minister of Personnel, saying that this was not in line with ancient laws, Emperor Gaozong never appointed him.
With such an identity, Li Chongrun must have made a name for himself when he grew up, but all of this was interrupted by Empress Wu Zetian. In the second year of Shangyuan, Li Hong, the eldest son of Emperor Gaozong of Tang, passed away. Five years later, Li Xian was deposed. Two sons died one after another, and Li Zhi had to appoint Li Xian as the crown prince. In December of the second year of Yongchun (683 AD), Emperor Gaozong of Tang passed away, and Emperor Zhongzong of Tang succeeded to the throne, with Wu Zetian serving as regent. At this time, although Li Xian was the emperor of the Tang Dynasty, he had no power at all. He understood that he was just a puppet of his mother, and dared not make any small moves for fear of causing death, following in the footsteps of his brothers such as Li Xian. On the sixth day of the second month in the first year of the Sisheng era (684 AD), Li Xian was deposed and Li Chongrun was demoted to commoner status. Li Chongrun, who grew up in such an environment, was very tolerant towards others. History records that he was known for his filial piety and friendship, unlike the descendants of sinners.
In the first year of the Holy Calendar (698 AD), Wu Zetian knew that all the sons of the Wu family were unreliable. Under the persuasion of Di Renjie, she reinstated Tang Zhongzong as the Crown Prince and appointed Li Chongrun as the Prince Shao.
In the first year of Dazu, Zhang Yi’s brothers were fortunate enough to meet Wu Zetian. They felt humiliated because Li Chongrun and his brother-in-law Wu Yanji had a lot of contempt towards them, so they “reported” the crimes of Li Chongrun and others to Empress Wu. They said they were discussing Emperor Wu privately, and Empress Wu was also very angry when she heard that Sun Tzu was “talking nonsense about the palace palace”. In order to beat Li Xian, she even killed Li Chongrun with a cane in anger. At this time, Li Chongrun was only nineteen years old.
After the restoration of Emperor Zhongzong of Tang, in memory of Li Chongrun, he posthumously honored him as Crown Prince with the posthumous title of Yide and was buried with him in the Qianling Mausoleum. He also invited the deceased daughter of Pei Cui, the magistrate of the Imperial Academy, to be buried together with Li Chongrun.