Li Qing (715-775), known as Li Mao (李瑁) from 725 and honored title Prince of Shou (壽王) was an Imperial Prince of Tang Dynasty, he was the 18th son of Emperor Xuanzong and his favorite concubine Consort Wu.
In 737, Emperor Xuanzong’s favorite concubine Consort Wu, trying to have her son Li Mao (originally named Li Qing), the Prince of Shou made crown prince, made false accusations against Li Ying (at the time the Crown Prince), as well as two other princes (Li Yao and Li Ju). Consort Wu had a message sent to the three princes, stating, “There are bandits in the palace. Please report at once in armor!” The three princes arrived in full armor, and she told Emperor Xuanzong, “The three princes are planning treason. Look, they have come in full armor.” Emperor Xuanzong had his eunuchs check out the situation, and the three princes were seen in full armor. The 3 princes were wrongfully accused of treason, reduced to commoner rank and forced to commit suicide.
Instead of Li Mao, Emperor Xuanzong was considering an older son, Li Yu the Prince of Zhong to become Crown Prince, but could not decide quickly, and was depressed over the matter as well as his killing of three of his own sons. Emperor Xuanzong’s chief eunuch, Gao LiShi suggested that the Emperor select the oldest one, since no one would dispute it. Emperor Xuanzong therefore made up his mind, and he selected Li Yu as crown prince.
At the age of 16, Yang Yuhuan married Consort Wu and Emperor Xuanzong’s favorite son, Li Mao, and then became Princess Yang. After Consort Wu died, Emperor Xuanzong was greatly saddened about the death of his then-favorite concubine.
At the age of 18, Gao Lishi led Princess Yang into the Huaqing Hot Springs and met Emperor Xuanzong. The emperor was greatly impressed by her beauty and wanted to take her as his wife. However, Princess Yang was already the wife of Li Mao.
Amidst protestations from his son, Emperor Xuanzong already in his 50’s forced Li Mao to divorce her, and arranged her to become a Taoist nun with the name Taizhen in order to prevent criticisms that would affect his plan of making Princess Yang his concubine. She then became the favorite of the emperor like Consort Wu was before. The Emperor renamed her Yang GuiFei (high-ranked imperial concubine) and arranged for Li Mao to marry another woman.