became arrogant, sexually immoral, and dictatorial, and he often executed officials, causing the nobles and the officials to be fearful. Zhang Tianxi's assistants Liu Su (), comparing Zhang Yong to Zhang Zuo, persuaded him that he needed to act against Zhang Yong, and later in 361, Zhang Tianxi had Liu Su and another assistant, Zhao Baiju () attempt to assassinate Zhang Yong, but failed. Zhang Yong then gathered his troops and attacked Zhang Tianxi, but Zhang Tianxi persuaded Zhang Yong's troops that he was avenging the Song clan and that Zhang Yong's next move was going to be to slaughtered the royal Zhang clan. Zhang's forces, hearing this, abandoned him, and Zhang Yong committed suicide. His clan was slaughtered, and Zhang Tianxi became sole regent. Zhang Tianxi ended the practice of using Emperor Min of Jin's era name Jianxing and instead started using the current era name of Jin Dynasty (at the time, Emperor Ai's Shengping), to show even greater affinity with Jin. In 363, Princess Dowager Ma, Zhang Xuanjing's grandmother and the mother of Zhang Tianxi's older brother Zhang Chonghua (Duke Jinglie) died, and Zhang Xuanjing honored his mother Lady Guo as princess dowager. She became concerned that Zhang Tianxi was acting dictatorially, and she conspired with the high-level official Zhang Qin () to kill Zhang Tianxi, but the news leaked, and Zhang Qin and other conspirators were put to death. Zhang Xuanjing became fearful and offered to yield the throne to Zhang Tianxi, but Zhang Tianxi refused. A month later, however, he had Liu Su lead soldiers into the palace to assassinate the 13-year-old Zhang Xuanjing, but claimed that Zhang Xuanjing died of an illness. Zhang Tianxi took the throne himself. He honored his mother Lady Liu as princess dowager, and he immediately sought out an official Jin commission as the Duke of Xiping, and released the Jin messenger Yu Gui (), who had been detained by Zhang Chonghua in 347 after offending him by refusing to grant him the Prince of Liang title that he wanted. Reign Zhang Tianxi's reign was regarded as one that was filled by arbitrariness, as he apparently allowed Liu Su, Zhao Baiju, and other trusted followers, none of whom was older than 20 years at the time of his ascension, govern as they wished. (He himself was 17 when he became duke.) He even formally adopted Liu and Liang Jing () as