苻登
After Former Qin began to collapse in 384 and Fu Jiān was killed by the Later Qin general Yao Chang in 385, Fu Deng became a subordinate of the general Mao Xing (毛興), who sought to control all of the provinces in the west still nominally under Former Qin rule, but his soldiers became weary from all of the battles and assassinated him in 386, replacing him with Wei Ping (衛平), a very old general who was the head of the clan. However, these soldiers soon became convinced that Wei was too old to accomplish much, and they deposed Wei and replaced him with Fu Deng. Fu Deng submitted a report of these events to Fu Jiān's son Fu Pi, the new emperor, and Fu Pi commissioned him as a provincial governor and created him the Prince of Nan'an.