engaging Ashina Helu. Meanwhile, as Empress Wang was sonless, her uncle, the chancellor Liu Shi, suggested to her that she ask Emperor Gaozong to create his oldest son Li Zhong, whose mother Consort Liu was of low birth and therefore considered nonthreatening, crown prince so that Li Zhong would be grateful of her in the future. Liu also persuaded Zhangsun to suggest the idea as well, and in fall 652, Emperor Gaozong created Li Zhong crown prince. By this point, however, Empress Wang was facing a major threat from another romantic rival. When Emperor Gaozong was crown prince, he had an affair with one of Emperor Taizong's concubines, Consort Wu. After Emperor Taizong's death, all of his concubines who did not bear sons, which included Wu, were housed at Ganye Temple () to be Buddhist nuns. In either 650 or 651, Emperor Gaozong was visiting Ganye Temple to offer incense to Buddha when 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. Meanwhile, Emperor Gaozong's sister Princess Gaoyang and her husband Fang Yi'ai (房遺愛, Fang Xuanling's son), were implicated in 652 of conspiring with another brother-in-law Chai Lingwu (), the general Xue Wanche () and Emperor Gaozong's uncle Li Yuanjing () the Prince of Jing to make Li Yuanjing emperor. Fang, knowing that Zhangsun had long been apprehensive of Li Ke, falsely implicated Li Ke in the plot as well, hoping to ingratiate Zhangsun sufficiently that he would be spared. nevertheless, in spring 653, at the suggestion of Zhangsun and Cui Dunli – despite Emperor Gaozong's initial inclination to spare Li Yuanjing and Li Ke—Emperor Gaozong ordered that Fang, Xue, and Chai be executed, and that Li Yuanjing, Li Ke, and the Princesses Gaoyang and Baling (Chai's wife) be forced to commit suicide. Zhangsun took this opportunity to accuse several other officials friendly with Fang or hostile to him—the chancellor Yuwen Jie, Li Daozong the Prince of Jiangxia, and the general Zhishi Sili