Wu Zetian's favorite son was Li Longji. In document 1, it was mentioned that Li Longji had fallen from a tall building when he was very young, but he was unharmed. This made Wu Zetian very surprised and liked him. In addition, in document 1, it was also mentioned that Wu Zetian had summoned all the imperial grandchildren to compete for rare treasures. Only Li Longji sat there unmoved, which made Wu Zetian praise him and give him the ancestral treasure, the Jade Dragon Son. Therefore, based on the information provided, it could be concluded that Wu Zetian's favorite son was Li Longji.

Wu Zetian's third son, Li Xian, ended up being poisoned to death by his wife and daughter. Li Xian did not have the heart of an emperor. He had always been treated as a puppet and was ordered around by Wu Zetian. In the end, he was poisoned to death by his ambitious wife, Empress Wei.
Li Zhi and Wu Zetian had a total of four sons. Among their sons, Li Hong was made Crown Prince at the age of four, but he died in 675 AD. The cause of his death was controversial. Some people believed that he had been poisoned by Wu Zetian. Li Xian was Wu Zetian's second son. He was deposed after being made Crown Prince and was forced to commit suicide in 684 AD. Li Xian was Wu Zetian's third son. He was relatively lucky to sit on the Emperor's throne, but in the end, he died at the hands of his woman, Empress Wei. As for his youngest son, Li Dan, he was the only one who died of old age.
Li Zhi and Wu Zetian had a total of four sons. They were Li Hong, Li Xian, Li Xian, and Li Dan. Among them, Li Hong died in 675 AD at the age of 23. There were two explanations for the cause of death. One was that he died of illness, and the other was that he was killed by Wu Zetian. In 684 AD, Li Xian was banished to a place and eventually committed suicide. Li Xian's ending was unknown. As for Li Dan, he had ascended the throne twice, but he had abdicated to his mother and brother three times. The final outcome was unknown.
Li Hong was the first son of Emperor Gaozong of Tang Dynasty, Li Zhi, and Wu Zetian. He was made Crown Prince in the year of Xian Qing Yuan. Li Hong was known for his benevolence and compassion, and he was praised by the people. However, he suddenly died of illness when he was accompanying Luoyang. He was only 23 years old. There were two explanations for his cause of death: one was death from illness, and the other was being poisoned by Wu Zetian. Most modern historians believed that he died of illness. Li Hong's death caused great grief to Emperor Gaozong of the Tang Dynasty. He made an exception and made Li Hong emperor, becoming the first crown prince to be posthumously conferred in the Tang Dynasty.
Wu Zetian's eldest son, Li Hong, died suddenly in the year 675 at the age of 22. There were two theories about his cause of death. One was that he died of illness, and the other was that he was killed by Wu Zetian. Most modern historians believed that Li Hong died of illness and not that he was killed by Wu Zetian. Li Hong was deeply loved by Tang Gaozong when he was young. He was also very smart, sensible, and very fond of learning. As the crown prince of the Tang Dynasty, he was highly praised, but because of his weak health, the later state affairs were handed over to others to handle. Li Hong's death caused great pain to Emperor Gaozong of Tang, so he was posthumously conferred the title of emperor.
Wu Zetian's third son's name was Li Xian.
There was a novel called " Wutang Strategy " about the protagonist who was reborn as Wu Zetian's son. The story was about the protagonist transmigrating to become Wu Zetian's son and gaining power through strategies. In addition, there was a novel called " Rebirth of the Crown Prince of the Great Tang." The main character had transmigrated to Wu Zetian's son, Li Hong. His appearance would have a major impact on the development of the Great Tang.
The eldest son of Li Zhi and Wu Zetian was Li Hong.
Wu Zetian killed his son. She gave birth to four sons. The eldest son, Li Hong, and the second son, Li Xian, died in her hands. Crown Prince Li Hong was honest by nature. Emperor Gaozong of the Tang Dynasty, Li Zhi, had the idea of letting him succeed the throne, so he gave him some power. However, Wu Zetian's power was supreme, and the mother and son had different political views, so the contradiction gradually deepened. In April of the second year of Shangyuan (675), the 24-year-old Crown Prince Li Hong suddenly died. Sima Guang recorded in Zi Zhi Tong Jian that Wu Zetian poisoned him. The second son, Li Xian, was made Crown Prince after his brother Li Hong died. He was rebellious and liked singing, dancing, and women, which made Wu Zetian dissatisfied and advised him many times. Later, someone reported his conspiracy and found hundreds of armors from the Eastern Palace. Wu Zetian was furious and deposed him as a commoner and sent him to live in Bazhou. He also sent Qiu Shenji to monitor him. After Qiu Shenji arrived in Bazhou, he let Li Xian commit suicide. Although Wu Zetian had a series of seemingly unrelated actions after learning the news, this matter was difficult to get rid of. "The New Emperor on Girls 'Day" is equally exciting. Everyone is welcome to click and read it!