姚苌
Later that year, against the much weaker Jin troops, Fu Rong's forces were nevertheless defeated at the Battle of Fei River—a battle that Yao Chang was not involved in—and Fu Rong was killed. In early 384, Murong Chui rebelled in the eastern empire, hoping to reestablish Yan, and upon hearing Murong Chui's rebellion, Murong Chui's nephew Murong Hong rebelled as well, near the Former Qin capital Chang'an. Fu Jiān sent his brother Fu Rui (苻叡) against Murong Hong, assisted by Yao Chang. Yao Chang advocated letting Murong Hong, who was intent on leaving the Guanzhong region to return to his homeland, leave, but the brash Fu Rui insisted on intercepting Murong Hong, and was defeated and killed by Murong Hong. Yao Chang sent messengers Zhao Du (趙都) and Jiang Xie (姜協) to report the bad news to Fu Jiān—and Fu Jiān, inexplicably, executed Zhao and Jiang in anger. Yao Chang became fearful and abandoned his troops, gathered the Qiang of the region, and rebelled himself, claiming the title of "King of Qin of 10,000 Years" (萬年秦王), thus establishing Later Qin.