When did Li Chengqian die?

Li Shimin's son, Li Chengqian, died in Qianzhou in 645 AD. Li Chengqian was demoted to a commoner and exiled to Qianzhou for treason. He died in a depressed and angry state in exile. Li Shimin was saddened by his death and buried him as a duke. As for the specific cause of Li Chengqian's death, the search results did not provide clear information.

Li Hong died in 675 AD at the age of 23.

Li Chengqian was made Crown Prince in 626 AD.

In 626 A.D.(the ninth year of Wude), Li Shimin ascended the throne as Emperor Taizong. On the tenth month, Li Chengqian, who was only eight years old, was appointed Crown Prince. The history books recorded that Chengqian was 'intelligent,''extremely intelligent,''graceful, dignified, and filial.' Taizong liked him very much, and as the Crown Prince of the Great Tang, Li Chengqian's life of being the second most important person to tens of thousands of people began.

Li Chengqian was made the crown prince two months after Emperor Taizong of the Tang Dynasty, Li Shimin, ascended the throne.

The exact year when Li Chengqian was deposed as Crown Prince was not found in the search results provided.

Yes, Li Chengqian rebelled. According to the contents of documents 1, 2, 3, 4, 5, 6, 7, 8, and 10, Li Chengqian chose to rebel because he felt that his position was threatened. His younger brother, Li Tai, gradually gained a group of supporters, and he felt uneasy about his position as the Crown Prince. In addition, Li Chengqian's expectations of Li Shiming were too high. He felt that his treatment was too different from his younger brothers, which made him feel very uncomfortable. In the end, Li Chengqian decided to take extreme measures and attempted to force Li Shimin to abdicate. Therefore, according to the information provided, it could be confirmed that Li Chengqian had rebelled.

[Li Chengqian did rebel.]

Li Chengqian had indeed rebelled. According to the contents of documents 1, 2, 3, 4, 5, 6, 7, 8, and 10, Li Chengqian chose to rebel because he felt that his position was threatened. His younger brother, Li Tai, gradually gained a group of supporters, and he felt uneasy about his position as the Crown Prince. In addition, Li Chengqian's expectations of Li Shiming were too high. He felt that his treatment was too different from his younger brothers, which made him feel very uncomfortable. In the end, Li Chengqian decided to take extreme measures and attempted to force Li Shimin to abdicate. Therefore, according to the information provided, it could be confirmed that Li Chengqian had rebelled.

Li Chengqian had indeed rebelled. In 643 AD, he attempted to seize the throne, and according to the laws of the time, Crown Prince Li Chengqian must be killed. As a father and emperor, Li Shi Min felt extremely painful and heartbroken when faced with the Crown Prince's rebellion. Although Li Chengqian did not regret his actions, he also realized that his actions might pay a painful price. As for what decision Li Shimin made, the search results did not mention it. Therefore, there was no clear answer in the search results regarding Li Chengqian's final outcome.