retreat from their original plans to destroy Former Liang, but the land south of the Yellow River could not be recovered. Also in 347, the Jin emissary Yu Gui () arrived in Former Liang to confer Zhang Chonghua a number of offices—but not the one that Zhang Chonghua was looking for, Prince of Liang. He tried to persuade Yu to grant him that title, but Yu would not, and so he detained Yu (who would not be released until 363, long after Zhang Chonghua's death). Zhang appeared to have largely stood by as Later Zhao collapsed during 349 to 351. Most of the western territory of Later Zhao fell into the hands of the Di general Fu Jiàn, who established Former Qin in 351. In late 352 or early 353, the ex-Later Zhao general Wang Zhuo, who had been holding parts of modern eastern Gansu and who had declared loyalty to Former Yan, could not resist Former Qin forces and surrendered to Zhang Chonghua, who treated him well, intending to use him as a general against Former Qin. In spring 353, he commissioned Wang, Zhang Hong (), and Song Xiu () to lead 15,000 men against Former Qin, but suffered a great loss—reportedly 12,000, or 80% of the army. Zhang and Song were captured, while Wang fled back to the capital Guzang (姑臧, in modern Wuwei, Gansu). In summer, however, Wang led 20,000 men and attacked Shanggui (上邽, in modern Tianshui, Gansu), capturing most of Qin Province (秦州, modern eastern Gansu). Zhang Chonghua then submitted a petition to Emperor Mu of Jin, requesting a campaign against Former Qin. Emperor Mu sent messengers to praise and bestow more honors on Zhang Chonghua, but the Jin government did not appear to be interested in attacking Former Qin at the time, so the plan was not carried out. Later that year, Zhang grew ill, and he designated his nine-year-old son Zhang Yaoling to be his heir apparent. His older brother Zhang Zuo the Marquess of Changning plotted with Zhang Chonghua's attendants Zhao Zhang () and Wei Qi () to take over power, and Zhao and Wei falsely accused Xie Ai of crimes and had him exiled from the capital to be the governor of Jiuquan Commandery (酒泉, roughly modern Jiuquan, Gansu). Xie submitted a petition accusing Zhang Zuo and Zhao of plotting, and in winter of that year, when Zhang Chonghua grew gravely