In 10 July 649, Emperor Taizong died, and Li Zhi took the throne as Emperor Gaozong. He created Crown Princess Wang
empress in spring 650. He also created her father Wang Renyou the Duke of Wei and her mother Lady Liu the Lady of Wei. Wang Renyou soon died thereafter and was posthumously given the honor of being
Sikong (司空), one of the
Three Excellencies. Her uncle
Liu Shi became one of the
chancellors. Despite the length of the marriage that Empress Wang had with Emperor Gaozong, she did not bear him a son, and by the time she became empress, he had already had four sons with his
concubines—and the mother of the fourth son
Li Sujie,
Pure Consort Xiao, who had also given birth to two daughters (the later Princesses Yiyang and Gao'an), was particularly favored. Liu Shi suggested to Empress Wang that she suggest that Emperor Gaozong's oldest son
Li Zhong, whose mother
Consort Liu was of low birth, be made crown prince, so that she could be endeared to him. Empress Wang was able to persuade Emperor Gaozong's powerful uncle
Zhangsun Wuji to support the plan, and in 652, Li Zhong was created crown prince. By this point, however, Empress Wang was facing a major threat from a different romantic rival. When Emperor Gaozong was crown prince, he had been attracted by the beauty of one of Emperor Taizong's concubines,
Consort Wu. After Emperor Taizong's death, all of his concubines who did not bear children were housed at Ganye Temple (感業寺) to be
Buddhist nuns. In either 650 or 651, when Emperor Gaozong was visiting Ganye Temple to offer incense to Buddha, he saw Consort Wu. Both of them wept. When Empress Wang heard this, she, wanting to divert Emperor Gaozong's favor from Consort Xiao, secretly instructed Consort Wu to grow her hair back, while suggesting to Emperor Gaozong that he take her as a concubine. Consort Wu was intelligent and full of machinations, and therefore, when she first returned to the palace, she acted humbly and flattered Empress Wang, who trusted her greatly and recommended her to Emperor Gaozong. Soon, Emperor Gaozong became enamored with Consort Wu. Both Empress Wang and Consort Xiao lost favor, and soon, they realized the seriousness of the situation and joined forces to try to alienate Consort Wu from Emperor Gaozong but were unsuccessful. In particular, Empress Wang was described as being unable or unwilling to make friends among Emperor Gaozong's other concubines,
ladies in waiting, and servants, a situation aggravated by the fact that her mother Lady Liu and uncle Liu Shi were disrespectful to the other concubines. By contrast, Consort Wu cultivated relationships with other concubines, ladies in waiting, and servants, particularly those that Empress Wang had offended, and she further distributed the rewards she received among them. So, Consort Wu took virtual control of the palace from the hands of Empress Wang, who was in charge of it, without her getting a whiff of the matter, and Consort Wu encouraged the crew both near her and at the palace door to spy on and slander Empress Wang. However, the situation came to a head in 654. Consort Wu had given birth to a daughter, and after birth, Empress Wang visited her. Shortly thereafter, the child was found dead, and the Empress Wang accused of murdering the girl. Consort Wu took this opportunity to convince Emperor Gaozong that Empress Wang had killed their daughter, with a view to get rid of Empress Wang (historians believe that Lady Wu's ambitions were such that she killed her daughter to oust Empress Wang). In summer 655, Consort Wu accused Empress Wang and Lady Liu of using witchcraft to try to gain favor back for Empress Wang, and in response, Emperor Gaozong barred Lady Liu from the palace and exiled Liu Shi. Despite this, he did not immediately depose Empress Wang. In fall 655, he summoned the chancellors Zhangsun,
Chu Suiliang,
Li Ji, and
Yu Zhining to the palace to discuss the matter—a meeting that Li Ji declined to attend. Chu fervently opposed deposing Empress Wang and pointed out that Consort Wu was previously Emperor Taizong's concubine and, therefore, taking her was considered
incest. Two other chancellors not invited to the meeting,
Han Yuan and
Lai Ji, also submitted opposition. However, after Emperor Gaozong asked Li Ji for his opinion, Li Ji responded, "This is your family matter, Your Imperial Majesty. Why ask anyone else?" Emperor Gaozong thus became resolved to depose Empress Wang, and in winter 655—November 16—both Empress Wang and Consort Xiao were deposed and reduced to commoner rank. Their mothers and brothers were exiled to the modern
Guangdong region, while Empress Wang's father Wang Renyou's posthumous honors were stripped. ==After removal==